New info from Kotaku's live postings on the press conference:
85 master tracks on disc.
Travis Barker and Haley Williams are playable characters.
Paramore will have a song in game.
Hot for Teacher was apparently played at the conference.
Metallica's new album available at launch as DLC.
Some more talk of Song, Rockstar, and Instrument creators.
Battle of the bands online, 4 v 4 online and any combination of local and remote play.
Oh and this interesting thing from the posts...
"there a port that allows players to play the game with any drum kit or beat box via a mini-in jack"
Didn't hear word yet on the whole setlist though >_< but the game's looking pretty awesome.
http://kotaku.com/5025653/activision-presser-liveblogging