This is Ampltude, in case you were wondering.
It sounds like the PSP is getting a sizable push at the conference, and the PSP version of Rock Band, titled Rock Band Unplugged, has been informally announced at the event. According to Primotech, which sounds like it's getting some leaked info from the conference, the game is being developed by Backbone Entertainment. It will feature tracks from Blink-182, Boston, Lit, Kansas, AFI, and more. It will also contain hooks for downloadable content through an online store.
The most interesting part is that the gameplay will be a lot like Harmonix's earlier releases for Sony, Frequency and Amplitude. Players will swap between different instrument tracks, complete phrases to trigger autoplay, and so on.
No release date has been confirmed, but expect it to hit this fall.
CF ftw xP
On a side note, I think the custom tracks feature will benefit a lot on the PS, with the easy saving and Sharing options!
Backbone developing and a weak tracklist? No, thanks.
Uhhh... Jeff, Just a note, you put AFI twice.