Rock Band "(Arguably) Punk 02" song pack, and discovered a song list for the game, including a large number of tracks that have yet to be revealed.
Unannounced tracks include "Zero" by The Smashing Pumpkins, "Pinball Wizard" by The Who, "Smells like Teen Spirit" by Nirvana, and "(I Can't Get No) Satisfaction" by The Rolling Stones. Songs in the cracked file were reportedly listed without artist names, but we're assuming each is based on the original artists' version (as opposed to, say, Britney Spears' cover of "[I Can't Get No] Satisfaction"). A song called "Still Alive" is also listed, which we can only hope is in fact Jonathan Coulton's song from Portal.
If true, it's a pretty sweet list of songs being added to the game. Of course, until Harmonix tells us officially, we'll keep this list next to the skeptical sauce; wouldn't want to get our hopes up if "Pinball Wizard" doesn't ever make it. Check out the list of possible new songs after the break.