If that leaked list of newcomers are for real, I can see over 9000 fans nerdraging and BAWWWing over the following:
- how Punch-Out doesn't need/deserve two characters
- Mewtwo and Roy aren't playable, especially Mewtwo
- how Star Fox doesn't need/deserve four characters
- the lack of females despite getting Palutena and Krystal
- how we should have gotten (favorite retro character) instead of Prince Sable
- how we didn't get a new Mario character
- how Isaac and/or Starfy aren't playable
- hating Slime for rightfully taking Geno's spot as the Square Enix
- how Sakuraiiiiiiiiiii!!!! is trolling us again with a horrible roster
But seriously though... most of them are pretty obscure even to the casual fans. The only ones I think non-gamers might recognize could be Little Mac, King Hippo (because of that Captain N cartoon), Mega Man, Sonic, Slime (at least to Japanese audiences), and of course the current poster child of Pokemon, Zoroark... and to a certain extent, King K. Rool.
If there were a few more familiar and well known Nintendo characters like Toad, Mii, Mewtwo and Meowth (because of the Pokemon movies and anime), Dixie Kong, even the Duck Hunt Dog (because of the Zapper and Duck Hunt that came with Super Mario Bros. and the NES in the 80's) and casual audiences may be more excited enough to be persuaded to get the game.
We had plenty of well known newcomers in Brawl. King Dedede and Meta Knight (because of the Kirby anime), Pit (because of that Captain N cartoon), Lucario (because of the Lucario movie), Pokemon Trainer (mostly because of Ash Ketchum and Bulbasaur, Charizard, and Squirtle featured in the first couple seasons of the Pokemon anime), Diddy Kong, Wario, Sonic, Toon Link (he is Link, enough said), R.O.B. (the robot that came with the NES in the 80's)... and to a certain extent, Zero Suit Samus (inspired by the Justin Bailey password in the NES Metroid). The ones I would consider relatively obscure could be Ike, Olimar, Lucas, Snake, and Wolf.
Even Melee was like this, too. We had well known newcomers like Bowser, Peach, Dr. Mario, Zelda, Ganondorf, Young Link, Sheik (because of Ocarina of Time), Pichu, Mewtwo, and Marth (to Japanese audiences). The fairly obscure ones would be Roy, Ice Climbers, Mr. Game & Watch, and Falco.
Going back to the first game in the series... the most famous ones are anyone who isn't Captain Falcon or Ness. Bottom line, the more famous ones always outnumber the obscure ones. That leaked list of newcomers is not following this standard. And I think I can safely determine this a fake. Hopefully fake.. JMO.