I tend to agree in that this isn't anything that new or revolutionary. Sure the topic seems cool off hand if you aren't paying attention however, Microsoft's Kinect essentially is the same thing. The only difference is you don't strap a Xbox360 to your back and walk around with it; which as CommonTater pointed out - why would you want to?
And I am sure Microsoft is planning on exposing the interface through the XNA framework so if you are willing to play with C#, and pay the membership fee) you could design apps like this as well. Probably something even cooler due to the processing power of the 360.