According to the latest issue of Jump, Project J Versus now has an official title. It is now called J-Stars Victory Vs. It was also announced that Naruto will be a playable character. J-Stars Victory is going to be a four-player 3D tag team fighting game. More information should be revealed once the official site opens up. Right now the countdown is at four days, so within the next couple of days, we will be able to access the website and hopefully learn more about the gameplay and most importantly, which other characters will be playable in this game.
Here is part of a scan of the issue of Jump announcing Naruto as a playable character:
J-Stars Victory is scheduled to be released on both the Playstation 3 and the Playstation Vita. An actual release date has not yet been announced.