Sony Santa Monica have been kind of quiet since the release of God of War III, even if they are helping out with Starhawk. A recent job ad over at Gamasutra reveals that they are looking for a "senior level designer", preferably with experience from open world games to work on an original title.
Good to hear that Sony Santa Monica have other plans going apart from the inevitable God of War IV. Hopefully we'll hear more about what they are up to in the near future.