French gaming website, >JeuxVideo will be announcing a major PlayStation 3 exclusive on May 2nd. According to the site, they will be doing a live video event on May 2, at 19:30 (presumably Central European Time) where they will announce a "mysterious PS3 exclusive".
PlayStation recently teased a reveal this Thursday, April 19th, which seems to be related to God of War. Whether or not this is the same game is unknown, but it seems unlikely that a Sony Santa Monica game would be revealed on a French website.
TheSixthAxis claims that the reveal could be related to a LittleBigPlanet MMO, which was hinted at through a job posting on the official LittleBigPlanet website.