Word would have it (or actually supererogatory tipped us off on Twitter) that the developers of Split/Second and Sonic Racing—Sumo Digital—are working on an exclusive title for the PlayStation 3 due out in 2013.
The reveal comes by accident, from the CV of one Naomi Summerscales, a freelance video editor and motion graphics artist (linkedin) at Sumo Digital. Her CV lists her as working as the "Creative Vision Holder on a Sony PS3 game due for release in 2013". She's also worked on promos for Sony for games like Little Big Planet, WipeOut HD, and as a level artist for LittleBigPlanet 2.
The smart money would suggest that the studio is developing a new racing game for the PS3. Only time will tell if that's the case.