The first Rock Band 3 DLC was revealed by the Canadian Gamestop's website. If you pre-order RB 3, you'll apparently be able to donwload the following three track for free:
- Talking Heads "Burning Down The House
- Deftones "My Own Summer"
- New Order "Blue Monday"
While the Deftones track is heavy, guitar-rock, the two other songs seem aimed at an older audience, and have prominent keyboard parts for the new peripheral.. in fact, they'd hardly work without the keyboard. I think that's the point!
Anyway, check out Gamestop's site if you want to look at this info first-hand.