Here are my predictions/hopes based on a 44 character roster: +2 transformations for a total of 46.
(6) 4 Mario reps: mario, bowser, luigi, peach 1 Yoshi rep: yoshi 1 wario rep: wario 4 zelda reps: link, ganondorf, zelda/shiek, new rep of some sort 4 pokemon reps: pikachu, newtwo, jigglypuff, lucario or new 2 earthbound reps: lucas and ness 3 fire emblem reps: marth, ike, 1 new rep (1 of chrom, avatar or lucina) 3 kirby reps: kirby, dedede, metaknight 2 kid icarus reps: pit, palutena 3 donkey kong reps: donkey kong, diddy kong, 1 new rep 3 star fox reps: wolf, falco, fox 1 f-zero rep: captain falcon 3 3rd party characters: sonic, megaman, namco rep (pacman?) 2 metroid reps: samus/zero, ridley 1 animal crossing rep: villager 1 ice climbers rep: ice climber 1 mr g&w rep: mr game and watch 1 nintendo rep: rob 1 wii rep: wii fit trainer 1 punch out rep: little mac 1 pikmin rep: olimar 1 golden sun rep: isaac
This gives 11 newcomers including: Isaac, Newtwo, FE:A rep, Palutena, DK rep, Namco rep, megaman, ridley, villager, little mac, and wii fit trainer.
And cuts: pokemon trainer (3 transformations takes up a lot of space and pokemon doesn't deserve to have 6+ reps), snake (when you look at other 3rd parties one of these things is not like the others, he feels more like a special one time addition), and toon link.