PopSci got an exclusive look into how Microsoft is creating a learning brain inside Project Natal to figure out just where your body is in front of your TV. It's impressive, to say the least.
Rather than programming by hand a way for the built-in computer in Natal to detect the thousands of ways the human body can move, they fed it thousands of shots of people in various poses. They also gave it mocapped video, which already had body points pinpointed. The resulting "brain", which is still under serious development, pinpoints about 30 body parts automatically and creates a wireform human figure 30 times a second.
It's fascinating stuff, so be sure to check out the full article. Natal should be out by the end of 2010. [PopSci]