+ London Studio
+ Noth West Studio
+ Pixel Opus
(+ XDev ? - ok, they don't create games by themselves but assist dev in Playstation exclusive games)
They also basically own QD and Bluepoint at this point. Also Sony works a lot with Insomniac games. Which will probably stick with Sony for a while now that their solo projects comercially flopped. But I am defenitely on board for either new or bigger studio's.
Please excuse my (probally) poor grammar