LaniusShrike
Smash Champion
Well, all the likely newcomers have something against them... but, assuming we see at least three new characters, I definitely think that K.Rool is among the top three most likely, even if he isn't necessarily the most likely. I'm going to be really weirded out if I'm wrong on this one... he's popular worldwide and first party, which is definitely more than can be said for a lot of other popular newcomers.