Okay, well, even though Gimpy was at E for All and gave a very good rundown on the current state of fox, I got to play as Fox first hand as well. Yes he plays a lot different than melee, but that's to be expected as this isn't melee. He is still fast, even sakurai said he was a speed character, but he's definitely not as fast as Sonic. From what I played of him (against a Link, Sonic, and Metaknight), he'll be fine in the final release. He's just not going to use the same style in Melee. A new Fox metagame will be found.
To be honest, I'm happy with the changes to Fox. Sure I enjoyed the overly buff Usmash and Uair, but just because those are "nerfed" doesn't mean fox will be a bad character overall.
Put it this way, Fox did fine for himself in the demo, he wasn't the best, but he wasn't the worst either, and there's still a plethora of characters that need to be added to the game from what we saw in the demo, which means he still has more time to prove himself.
For those who are hoping for a complete revamp in the final release, don't get your hopes up, the February extension was for Online features, if there ARE any tweaks to fox to be made, don't expect them to be anything beyond a few timing issues or MAYBE the Shine cancel fix.
As for me, I will still remain the loyal fox player till the end. Smash 64, Melee, and Brawl, becuase he's such a great character.