A patent filing by Sony Computer Entertainment seems to suggest that the PlayStation 4 could be set to have its own motion tracking camera similar to Microsoft's Xbox Kinect.
Described as "an invention [that] is provided for affording a real-time three-dimensional interactive environment using a depth sensing device", the patent filing reads like a clinically explained Kinect camera. While Sony has been pushing for increased uses of its Eye Camera and Move motion hardware, having hands free motion tracker would certainly open up new avenues of gameplay and console interaction on a PlayStation - in the same way as Microsoft's hardware has.
Sony's filing describes the device as having a specific depth range, with distances being mapped and registered. "Objects" - presumably referencing people as well as static objects - are then "rendered and displayed in a virtual scene" based on its geometry and placement. The depth of the object is said to be determined by infrared, which is similar to how Kinect works.
By understanding how far from the camera certain parts of "objects" are, it creates a 3D virtual environment which should allow for all the sort of interesting effects and interactions that Kinect development has brought about. Whether it's real time facial manipulation or gesture controls.
While there is little mention of the application of this new system - and no mention of the PS4 - the filing does say that it could be used in a "video game system" as well as being attached to the PlayStation brand.
It's a little late in the day to expect this new development to be twinned with the six year old PS3, so expect mentions of this 3D camera to come alongside the first hints at the PlayStation 4 sometime later this year. Perhaps at E3.