Eh, never-mind. I'll do a write-up now rather than later. Since this is on the Kirby Boards, I'll write it from the perspective of a Kirby player. I’m borrowing and slightly altering t1mmy’s format because it works really well. Hope you don’t mind, t1mmy! 
I apologize in advance if I missed something. Please point it out if I did. Also, I won’t talk about stages until Viper wants to discuss DK in the stage thread.
Kirby vs. Donkey Kong
DK has traits that Kirbys love (big target, combos fairly easy, has a blind spot below him and in front of him in the air) as well as traits that Kirbys hate (REALLY hard to kill without a gimp, most of his spacing tools are far superior to Kirby's, kills Kirby at ridiculously early percents). The Match-up is full of extremes and lacks common ground, so whoever has the match's momentum in their favor tends to do the best, no matter what tools either side has. Also, out of all of Kirby’s Match-ups this one is the poster child for the phrase “don’t get hit!”
Long range
This range will very likely not happen much in this match-up unless one of the two characters has been sent flying, and after that it will be straight back to mid or close range. DK has no projectile to force an approach from Kirby, but if the Kirby decides to use final cutter they should be aware that DK is one of the most mobile characters in the game (his movement is close to on par with Marth's minus air acceleration and plus a faster Fast-Fall speed) and can close the distance easily to punish. The Kirby can throw it out every once in a blue moon if they can ledge cancel it or use platform mind-games, but in general shouldn't use it. DK can punish HARD for any mistakes.
Even though it isn't a projectile per-say, I'll mention DK's down-b here. The range on this move is about a DK d-tilt length behind him and about 2 d-tilt lengths (!) in front of him. The Kirby player should never assume they are safe on the ground in general proximity of DK. DK can use down-b to pop Kirby into the air for follow-ups at long range, punish spot-dodges and rolls or use it to get Kirby off of him at close range if used correctly. The only saving graces for Kirby with this move are that it doesn't hit anything airborne and is very punishable by things like giant swing if Kirby is in the air before the move hits.
Mid Range
This is going to be where DK is going to try and keep Kirby for a majority of the game. DK's moves in general have a bit of ending lag and are on the linear side, but that won't make them easy to get around. DK's f-tilt out-ranges almost all of Metaknight's move-set to give you an idea. The key here is for the Kirby player to try and vary their responses to his approaches and try to punish anything missed with a grab or combo starting move like u-tilt or in some cases d-tilt. The f-tilt->u-air combo only works through the u-air if DK DI's correctly, but it still puts him in a defensive position without any combo breaker to speak of (he has a few tricks, and I'll get to those later). D-throw also puts him in a bad position due to his weakness to quick attacks from below in the air.
Its easy to say on paper, but in reality its much harder to do. If the DK spaces correctly he can keep Kirby at bay for a long time. F-tilt can be aimed at either an up or down angle and has monster range and comes out pretty quickly (8 frames up close, 9 at the full distance of the move), d-tilt is fast (6 frames close, 7 frames at full distance) and has little ending lag (though it can't be aimed so it is more limited in application than f-tilt), and reverse u-tilt can knock Kirby away if he tries to close in from above. Whats more is that it only takes getting hit around ten times or so with tilts to be put into KO range. At the end of the day, the Kirby player will need to outsmart the DK to get in. Shield-grabs, running spot dodges and low flying aerial antics can do the trick as long as the Kirby isn't predictable about it.
Another thing to be aware of is that most of DK's kill moves are used around this range as well. A fresh f-smash and u-smash can kill around 80%, with d-smash not far behind around 95% (with decent DI and momentum canceling. Without it, it probably closer to 70% and 85% respectively). All of them come out relatively fast for their power. Giant punch also kills at a low percent (just a bit lower than f-smash), with a 9-wind killing around 60% (!) unless the Kirby has really (and I mean REALLY) good DI and momentum canceling. If you don’t DI and momentum cancel, a fresh 9-wind can kill under 50%.
Close Range
This is generally where Kirby wants to be. DK's tools become much more limited at this range, with his standing grab being 8 frames and his jab (tied for his fastest move) being 5 frames. Kirby's grabs allow for follow-ups because of this, and he can put the hurt on DK at lower percents. This is also the general range Kirby needs to be in to score an outright KO, seeing how even Kirby's f-smash is out-ranged by most of DK's moves.
DK isn't completely defenseless at this range however. Though it doesn't hold a candle to his other moves range-wise, DK's jab still has decent range on it and can disrupt a lot of Kirby's attempts to close the distance. DK's d-tilt and u-tilt come out on frame 6 and 5 respectively at close range as well, so even though Kirby out-speeds DK at this range, it isn't by too much. DK also has his grounded up-b and fully charged Giant Punch at this range, and here is where DK's greatest counterattacks come into play. Up-b is slow to come out (first hit-box is on frame 19) and doesn't have much range to it (comparatively), but it has SA on it from frames 10-16. With those frames DK can over-ride just about any attack Kirby can throw at him. The giant punch has similar properties, with the first hit-box on frame 18 but SA frames on 17-20. Both of these move can deal out ~30% damage (less on the up-b with SDI, but Kirby has to be quick about it) and the Giant Punch can kill. Even if the moves don't do full damage, they will reset the positions to DK's advantage again. If the DK player is any good at timing the SA frames, the Kirby player will be vocally cursing the programmer that created them.
Another thing to be aware of is DK's grab game. His grab is slow, but has great range on it (just a tad less than DeDeDe's) and he can put Kirby on his back and cargo carry him around until he breaks out. The cargo tosses can put Kirby in bad positions too, anything ranging from straight up for u-air follow-ups to just off the edge for a quick dair spike. The regular throws aren't bad either, with the back throw and d-throw putting some distance between the characters and resetting DK's spacing game.
Air
This is the most polarizing part of this MU. Either Kirby is at a distinct advantage or disadvantage here, never in between. DK’s bair is one of the best bairs in the game. It has more range than anything Kirby has in the air save for final cutter, comes out fast (on frame 7) and can kill at decent percents if fresh (~120% at long distance, lower if near the blast-line and since DK can’t use it to approach Kirby because of Kirby’s short height, its much more likely that it will be fresh). DK’s u-air is also good, coming out a bit faster than bair (frame 6 just behind DK's head), when fresh killing around 100% (again, lower if near the blast-line) and covering a good portion of DK’s upper body in the process. If Kirby is either behind DK or above him in the air, DK will most likely win out.
If Kirby is in front of or below DK in the air, its an entirely different matter. DK’s dair is the third (second?) most powerful spike in the game, but it doesn’t come out until frame 18, which is more than enough time to capitalize. The move also has a lot of ending lag, so Kirby can bait the attack and then punish with a grab, tilt, or well timed smash even. In front of DK is a bit more complicated, but still a weak point. DK’s options are nair (first hit is on frame 10, but the hit-box is very specific and hard to connect with) fair (first hit is on frame 25, which is WAY more time than Kirby needs to capitalize) Giant punch (which hits on frame 18 if fully charged, but not until frame 25 if not. It is also good to note that DK goes into helpless mode after the punch) and u-air (its hit-box extends a bit in front of DK, but only on the top portion of his body and is easily avoided as Kirby). None of these moves are reliable, so Kirby simply needs to out-speed DK with any of his aerials if he is in the right position to do so. Its also good to note that DK can use his side-b in the air too, but the hit is weak, has relatively little range and is slow.
Off-stage: DK’s Recovery
This is yet another aspect of the MU that is interesting. Kirby’s best bet for a kill is an outright gimp because of DK’s survivability, and at first glance it would seem to be easy to do. Generally speaking one dair, no matter how small the amount of time DK spends in it, is enough to pull off a successful gimp. A smart DK has all the options they need to defend themselves on their way back to the stage though. Off-stage, DK can use fair to cover a large portion of his hurt-box on his way back down to the stage, and it can be dangerous for a Kirby to challenge it if they aren’t close enough at the start of the move. The move either knocks Kirby back with a strong hit, allowing DK time to recover, or spikes Kirby hard, allowing for the same plus an opportunity for DK to gimp. DK can also use side-b in the air to aid his recovery. Although it’s not a very good attack damage and knock-back wise until later percents, DK can use it to stall. If the Kirby gets hit by it, it’s a weak spike, so DK is again in a favorable position to recover. DK’s up-b has a lot of priority on it as well, and covers massive horizontal ground, as well as lasting a long time (long enough so that Kirby won’t likely be able to ledge hog unless the DK is a large distance away from the ledge when he up-bs). The up-b also has invicibility frames on it while in the air, so DK can outright override some attempts at gimps simply by trying to recover. One final note: DK can recover directly to the platform with no lag if he uses up-b at the right time off-stage. This give DK a LOT more options for recovery when there are platforms available. Even with all these tools though, Kirby still only has to pull off a single (on VERY rare occations, two) dair to pull off a successful gimp and should be looking for any opportunity to do so.
Off-stage: Kirby’s Recovery
If the positions are reversed, the off-stage game very much resembles the aerial game. DK will most likely attack with his back turned for easy bair and u-air kills off the sides and top respectively. Kirby needs to be very aware of DK’s position when recovering close to level with the stage as well. DK has three spikes with which to gimp (two being nearly overpowered for how hard they hit) and can recover back to the stage fairly easily even if they miss. Kirby has a lot of off-stage staying power though, so DK will not likely go for the spike unless Kirby wanders too close to the stage without many jumps left. Kirby has a lot of options to deal with DK’s attempts to edge-guard since he has multiple jumps, but the player should be very wary of making a mistake due to it being outright deadly to do so. It should also be noted that recovering is a prime time to attempt a gimp if the Kirby is feeling brave. Dair still works it's magic on DK, and Kirby-cides are an option if Kirby is at a higher percent. The Kirby should be aware however that DK can footstool Kirby after an inhale release, reversing the gimp situation.
KO options
I’ve already gone over DK’s KO options a bit, but I'll go over them in more detail here. F-smash is in general the slowest option DK has (frame 22) and has no set-up on Kirby, but it has even more range on it than DK's f-tilt and a slight disjoint on the tip of his fingers. The move also comes out on frame 8 after a charge, so a punish happy Kirby may find themselves flying if they aren't careful. DK's u-smash is the most situational of his KO options, but can still be useful. Any time Kirby is on a platform above DK is an opportunity for DK to use the move. Unless the move is perfect shielded, it provides enough hit stun to be virtually un-punishable. The move also sends Kirby sliding along the platform and can put Kirby in helpless fall state if he falls off of it, giving DK time to punish. DK can also set this up by using down-b, but it is not guaranteed by any means. DK's d-smash is the weakest of his smash moves knock-back wise, but by far the easiest to use because of its properties. The move hits on both sides of DK and has no sour-spot to speak of, meaning if it hits, it hits hard. DK also has set-ups for this KO move, the most notable being a tippered jab above 100% and an aerial up-b->lagless landing->d-smash. The latter can also rack up a lot of damage before the hit, so its best to be careful when DK has the option.
DK's Punch is one of the most fearsome moves DK has in this match-up, and the Kirby player should be aware AT ALL TIMES how many times he has wound around his arm. The move only really works as a damage racker or a way for DK to get Kirby off of him at anything less than 9 winds. Once DK has wound his arm around 9 times though, the use of the move changes. At this many winds, it turns into one of the most fearsome KO moves in the game. It comes out in 25 frames (18 if DK is winding up when he releases it) and has the potential to kill Kirby under 50%, even with DI. At a full charge, the move loses some power (it becomes just a bit stronger than an f-smash), but gains super armor. With the SA frames, the move can be used as a very deadly counter attack. DK's giant punch has no reliable set ups, but it has them none the less. Any time that DK's side-b move plants Kirby into the ground is an opportunity for DK to land this move. DK can also reverse it while charging or in the air, so the Kirby player should never assume that they are safe from it when DK's back is turned.
I'll also mention again here that DK's bair and u-air can kill over 100%. One final thing to note: DK's b-throw can kill at percentages over 150% with DI, but it isn't likely that Kirby will be living that long in this match-up.
Now, on to Kirby’s KO options. With DI and momentum canceling, DK is the heaviest and hardest to KO character in the game. The only way Kirby is going to get a KO under 110% is going to be a gimp. DK will easily be surviving above 160% on average on the stocks that he isn’t gimped. Side KOs work best, with the trusty f-smash and hammer providing the biggest bang. Tippered d-smashes might also set up for gimps even if they don’t kill outright. Kirby shouldn't bother using u-smash unless DK is about 150% though. If the DK is good at DI and momentum canceling, he will simply fall back to the stage as if nothing happened. If Kirby has a chance to gimp, he should take it. If he doesn’t, he will have a very long and arduous road ahead of him trying for that outright KO.
It would probably be good to mention Kirby's DK power here. The range on Kirby's version of giant punch is severely limited compared to its original form, but is just as powerful. 9-wind punches and SA are both transferred to Kirby's version, and both 9-wind and fully charged punches are more powerful KO options than anything else Kirby has save perhaps hammer. Star-shot gimps are good against DK as well though, so it would be up to the Kirby player to decide which ability they would prefer.
Summary: 45-55 Donkey Kong’s advantage
Anything you didn't say was covered by everyone else.
