No thanks, that would cause too much non-sense with picking certain characters for certain things. Like if I loved playing a mini-game, but the only way to win mini-game is to pick a character who's good at it like Wario and not Peach (who I use all the time). I wouldn't like if it was something like that.
HOWEVER, if it is like MP7 where everyone gets a special Item or whatever, that's fine, I don't mind each character getting a special item.