Honestly, I know it's too much, but I'd honestly like to see some of the characters that have similar movesets to merge. Like instead of having Falco kick the reflector, just give Fox/Falco the same movesets with different stats, and let Falco and Fox be the same style of character. Kind of like how in Tekken 5 Eddy and Christie have some different things about them give or take, but if you can use one, you can use the other and they were actually on the same character. I can only imagine that saving them some time.
Black Shadow for Ganondorf's moveset, and then merge Captain Falcon and BS into one character selection.I really don't want to see any characters leave. Because nothing sucks more than having your favorite character leave. And for the love of god I hope that characters aren't DLC for this game... Seeing Fire Emblem on the 3DS though... Doesn't make me hold much hope for that though.
So I hope that Wolf stays. Like everyone else. Snake and Sonic are the only ones that I can understand leaving. At least if Snake leaves though, I hope his moveset is preserved for someone. Maybe give it to Anthony for Metroid? I know most don't like Other M, but he was at least one thing good that came out of it. It gave Samus a friend.