The Beatles: Rock Band got Nominated for Best Use of a Creative License(winning), Best Music Game(winning), Best on the 360, Best on the PS3, and surprisingly Game of the Year.
Rockband 2 got nominated for Best DLC.(Should be winning. Dumb Fallout)
Congrats Harmonix, you obviously got a winner with TB:RB.
EDIT: It was nominated for Best Wii Game. Which it might deserve. Maybe behind SMB.