Mario, Luigi, Peach, Bowser, Donkey Kong, Link, Toon Link, Samus, Pikachu, Fox, Pit, Kirby, Olimar, Sonic, Mega whatever, Villager, Pale fitness lady. Now that the confirmed are listed, I'll bring in my predictions.
I pretty much guarantee he'll appear, for obvious reasons.
Again, another obvious one.
Do I even need a reason?
Windwaker Ganondorf/Toon Ganon
While there's nothing wrong with normal Ganondorf, this would be a far better choice for making him his own character, and not just a clone.
I dunno why, I just feel they'll probably reintroduce him.
A classic, although this time around I predict they'll make his moveset a -little- more unique.
Mr. Game and Watch
They've had him for two games now, why get rid of him? Plus his uniqueness is still relevant.
DK's sidekick, a perfect addition.
Marth has remained pretty relevant.
Another Fire emblem character
Unfortunately, Im not very versed in Fire emblem, but I suppose just fill in the blanks here.
Lip has been referenced a lot throughout Melee and Brawl, through music, stickers and even her own weapon. Sakurai recognizes the original Panel de pon as a masterpiece. Her inclusion just seems like a no brainer.
Was a good addition in Brawl, why not?
With Namco helping development, this isn't too far fetched.
With her gaining relevancy in the newest installment of the DKC series, I think this would be a good choice.
Some other pokemon
Again, dunno much, so fill in the blanks.
So that rounds off the roster at a nice 32 characters. Less than Brawl, more than Melee.