We pride ourselves on knowing pretty much everything there is to know about Kinect, but we're not infallible Kinect-powered robots: sometimes we miss things. This is one of those things.
While there are still no Kinect-enabled games to download on Xbox Live Arcade, there's already an Indie game available: Avatar Superstar for 80MSP. It's a singing game that uses Kinect or a Lips microphone to register your warbling, though we don't know too much about it at this point.
Of course we'll be bringing you a full review shortly. Hopefully the game's "SuperTune technology" can transform our tuneless caterwauling into the sort of beautiful sound of an angelic choir.