And it wouldn't be a "patch" per se, even though it could be integrated into any RB2 game save. I may have to change my pants if HMX already has this plan up its sleeve.
TAGged but not bagged!
DLC: Blind Guardian, 3, Dio, Cynic, Devin Townsend, Death, Ihsahn, Opeth, Nevermore, Dream Theater, Symphony X, Kansas, King Crimson, Queensryche
The wii doesn't allow patches because nintendo is scared of technology. So you'll have to wait for rockband 3 at best. But... you could get some of the RBN songs as dlc. Kind of sad but not harmonix's fault.