Xbox.com has launched a new Xbox TV section, presenting a series of trailers for Xbox games in Windows Media 9 format. So it's partly to promote the games, and partly an exercise in distributing WM9 codecs.
There's a small selection so far, but expect to see more soon. To begin with, there are "Photo stories" of both Kung Fu Chaos and Halo 2, with high resolution captures and concept art, and a trailer for Tao Feng, the beat 'em up former Mortal Kombat creator John Tobias is working on.
Xbox TV can be found here.