This just in from joystiq:

http://www.joystiq.com/2008/01/18/rock-band-songs-tops-2-5m-downloads-200-songs-in-pipeline/

Rock Band wannabes have downloaded more than 2.5 million additional songs trumpets MTV, exceeding the game publishers expectations and opening up a new stream of revenue for a "challenged" music industry. The most popular downloads have been 3-song packs, led by the Metallica bundle, and The Police and Queens of the Stone Age collections. As for individually downloaded tracks, the "Juke Box Hero" cover has taken top billing, followed by the "Fortunate Son" cover and Weezer's "Buddy Holly". Not surprisingly, all of the top downloads except "Buddy Holly" were included in the first DLC release.

With more songs arriving each week, Rock Band has made Guitar Hero III's sporadic DLC updates look like an amateur act (though Activision's sequel has a considerable lead in total software sales) – and there are no signs that MTV and company are letting up. More than 200 downloadable songs are currently in the pipeline for 2008, including long-awaited full album releases and music directly related to gaming (similar to GH3's Halo track), reports IGN. Paul DeGooyer, Senior Vice President of MTV Games, explained that this massive DLC commitment "changes the approach [for a sequel] from one that's purely about new music to one that's about new features." This suggests that if there is a Rock Band sequel, we'll be able to tote our millions of downloads along for a second tour. Rock on!
 

And it's here too:

http://www.vgchartz.com/forum/thread.php?id=14800&start=0#end

Yes but that's in the boring "General Gaming" forum.

Haha ... at least you (and me) are earning VG$!!!!!

wow thats alot of download i think a sequel is most likely confirmed

There better be a sequel.
I can totally see Guitar Hero (next one) adding support for drums, bass, mic because of this game.

^i think if they add those they would have to change the name,though a mic is likely