Microsoft invited the Verge to see a demo of the Xbox Smartglass functionality built into Dance Central 3 for the Xbox 360.
The 2nd screen app allows participants to easily select / queue tracks and change settings in the game without using the controller, and should work on a wide variety of both Microsoft and non-Microsoft devices.
The Smartglass App is apparently finished and ready to go and will hopefully hit the market in time for the holiday season dance offs.
Via The Verge.com