M$ has the same disease that Apple has, and most other big companies have.
They are control freaks. They are scared what will happen if we just let people use the technology how ever they want.
Might be old hat to you guys. But i did not know it used IR light like a radar.
http://www.wired.com/gadgetlab/2010/11/tonights-release-xbox-kinect-how-does-it-work/Everyone has been trying to just use a cam by itself. So simple it is brilliant

Also amazing they can sell for only $150 and still make a profit.
The military tries to make shit like that, it would cost $400K per a unit.
Probably be the size of a small suitcase, weigh 20kg, and still be called "portable".
Probably it would also need some sort of special expensive batteries which are about the size of small car battery and last for only 10 hours.
Those would weigh 5kg a piece and would me "man portable" also.
Anything under 50kg is man portable according to the military.