The camera resolution is fixed by the hardware. I think they'd have to wait until a better Kinect is built. That said, you COULD go the way of several hacks I

The camera resolution is fixed by the hardware. I think they'd have to wait until a better Kinect is built. That said, you COULD go the way of several hacks I've seen - marry a high resolution external camera to the Kinect rig, do the correspondence, and use the external camera as your face recognition input.