Last Month, Matt Paprocki from Multiplayergames.com says (in Patch: Rock Band 2 Now Supports Wireless Mics on 360) One of the requested features for Rock Band 2 users has been implemented with a title update on the Xbox 360, allowing support for wireless microphones such as those included with Lips. The Rock Band forums divulge all of the details, including background downloading of all songs purchas...

And Shacknews says (in Rock Band 2 Patch Brings Wireless Mic Support) An update for the Xbox 360 edition of Rock Band 2 was released by Harmonix today, delivering the long promised support of the Xbox 360 Wireless Microphones that come bundled with Lips and were recently released for standalone purchase. The Xbox 360 incarnations of recent music games rele...