> Sony is building its CPU on what it's calling an extended DirectX 11.1+ feature set, including extra debugging support that is not available on PC platforms. This system will also give developers more direct access to the shader pipeline than they had on the PS3 or through DirectX itself. "This is access you're not used to getting on the PC, and as a result you can do a lot more cool things and have a lot more access to the power of the system," Norden said. A low-level API will also let coders talk directly with the hardware in a way that's "much lower-level than DirectX and OpenGL," but still not quite at the driver level.

source: http://arstechnica.com/gaming/2013/03/sony-dives-deep-into-t...

edit: that said, I wouldn't be surprised if there was an OpenGL stack available for ps4, especially if they want to attract indie-devs.