Something Sony didn't go into great lengths to explain last evening was the PlayStation 4 Eye. The device has two high-definition stereoscopic cameras which will allow the device to triangulate positioning in a three-dimensional space. This allows for motion gesturing, head tracking, and body mapping for direct implementation into games.
It has potential applications for augmented reality games. One cool aspect of having two cameras is one can be dedicated to making the picture look great while the other focuses on recording movement. A second use for the cameras is the ability to take 3D pictures. The device features a full microphone array to cut out noise, tell which direction voice is coming from, find out who is speaking, and focus on that particular person.
Voice recognition could also extend to command features. Sony, however, isn't ready to talk about that just yet and we will know more about the device's functionality in the future.
via destructoid http://www.destructoid.com/details-regarding-playstation-4-eye-camera-device-246234.phtml