Realistically, I think the roster will stop at 35. Going above it would be ludicrous. Technically, Sakurai and his team can do it (if the Mortal Kombat team, the Capcom team and the Atari/Dragon Ball team are able cram more than 50 characters in their respective fighters so can Sakurai), but he gotta leave some characters for the fourth game...That is IF there is a foruth game O.O .