Some interesting additions to Guitar Hero: World Tour coming in December, most notable are three tracks from Nirvana including one from the band's Sub Pop Records debut, Bleach. The track, "Negative Creep," will be featured along with the non-album single, "Sliver" and "You Know You're Right," which was released posthumously on 2002's Nirvana [Greatest Hits].
Update: Oops. That's Guitar Hero: World Tour, not Rock Band 2. Sorry about that.