The patent app is titled Real-Time Camera Tracking Using Depth Maps and the abstract reads:
Real-time camera tracking using depth maps is described. In an embodiment depth map frames are captured by a mobile depth camera at over 20 frames per second and used to dynamically update in real-time a set of registration parameters which specify how the mobile depth camera has moved. In examples the real-time camera tracking output is used for computer game applications and robotics. In an example, an iterative closest point process is used with projective data association and a point-to-plane error metric in order to compute the updated registration parameters. In an example, a graphics processing unit (GPU) implementation is used to optimize the error metric in real-time. In some embodiments, a dense 3D model of the mobile camera environment is used.
Per Game Trailer:
The environment sensor would use the Kinect's ability to determine trajectory and depth to create a digital map of the area it is seeing. It can also track itself through a motion detector such as a smartphone accelerometer. The technology, however, isn't just limited to mobile devices. Microsoft hopes to work the mapping capabilities into smartphones and PCs.