According to wii.qj.net, Lady Gaga & Eric Cartman (whaty what?) will be on the upcoming rock band.
http://www.youtube.com/watch?v=q4ybq...layer_embeddedLady Gaga has consistently been the voice on the radio, the music in bars, that Last Song Syndrome in your head. Her songs have been playing everywhere - so much that even Eric Cartman couldn't resist singing along. Pretty soon, you'll have a few of the pop star's music right in your Rock Band archive as well. As an added treat, you can also get Cartman's version of Poker Face
via KotakuLady Gaga Pack 01 will include "Poker Face," "Just Dance," "Monster," and "Bad Romance." The South Park Poker Face track will not be included in the pack, but will also be available to download at the usual rates. They'll all be hitting the Wii, PS3, and Xbox 360 at their respective online stores next week.