Sure, Green Day: Rock Band sees Harmonix taking yet another page out of Activision's book entitled "How To Make Us Sick Of Your Music Franchise", but it does have one advantage over its predecessor, The Beatles: Rock Band.
That game was self-contained. If you wanted to play The Beatles' songs in another version of Rock Band, tough, you couldn't. But Green Day: Rock Band will do nothing of the sort, and will feature "a fully exportable track list that will allow users to play the songs in "Rock Band" and "Rock Band 2" on the Xbox 360 and PlayStation".
Wii users, meanwhile, will just have to make do.
Amazing how the power of technology can make the band appear as if they aren't too old for this stuff.