Sony has registered the web domain for "PlayStation All-Stars Battle Royale," which is reportedly a "Super Smash Bros." style game that will feature all of your favorite Sony characters instead of Nintendo characters. Sony also registered "PlayStation All-Stars" (or, more accurately, http://playstationallstars.com/.)
We know that Sony is planning on revealing a "huge" new game on Thursday, and it could very well be this one. We'll keep on top of it and let you know more when we know more. If that doesn't happen, we very well may see the game at E3 2012.
Source: PlayStation Lifestyle