In addition to the announcement of One Piece: Pirate Warriors 2, it seems Namco Bandai is working a mysterious game called Project Versus J. This game was also revealed in an advertisement, which showcased nothing more than Luffy (One Piece), Son Goku (Dragon Ball), and Toriko (Toriko) with the games title.
While not a lot is known about the game, it seems to have a resemblance to Battle Stadium D.O.N., as it was also a cross over fighter featuring 3 series. (Dragonball, One Piece, Naruto) However, I’ve heard a number of reports claiming that Namco Bandai was accepting series nominations, so this could mean the game is closer to Jump Super / Ultimate Stars. Hopefully more information will be released soon and ideally this will be on the PS3 / Vita, since this title will most likely not come stateside.