It's an understandable decision, Not because Kinect is'nt any good, it just doesn't fit, with the style of the game.
I can see Natal working brilliantly with point and clicks or RTS games, maybe head tracking in FPS's although that could prove to be awkward.
the lack of an actual controller makes it's uses limited. Unlike move/wiimote which are just new controllers and already proven to work with core games.
Comedy. gaming. Lemmings? You do the math www.laserlemming.com