In the latest Rock Band preview over at IGN (who are apparently playing this game more than we are, thank you very much Harmonix/Electronic Arts), it has been revealed that the R.E.M. track, "Orange Crush," will be playable. Additionally, folks over at the official Rock Band forums (who are not playing the game, just talking about it ... a lot) have poked around the Internet and uncovered a few unannounced bands and tracks. 

On their official site, Christian metal band Flyleaf had apparently let slip that their single, "I'm So Sick," would appear as an unlockable song in the game. It seems someone jumped the gun, as the post quickly disappeared; once again, Internet cheetahs were able to snag the slippery text, reprinting it on the game's official forums.

But there's even more Rock Band track news slipping through the Internet's cracks today. In a MySpace bulletin, Anarchy Club singer/guitarist Keith Smith revealed that a track from their new E.P. will appear in Rock Band. Smith (who also a Harmonix employee) also reveals that previous Guitar Hero unlockable favorite bands like Bang Camaro, Freezepop, Acrobrats, and Vagiant will appear in Rock Band as well.

On another note, if you were one of the few people who had a mini-heart attack at Amazon's little practical joke (where they changed Rock Band's release date to August of 2008!), never fear. Harmonix reps assure us that the game is still very much on track for a November release date.

[Thanks, Xzyliac!]