For the record, also confirmed are:
Death Cab for Cutie
Cold War Kids
Autolux
Turbonegro
Austin TV
It's also looking like The Verve, The B-52s, Portishead and Caribou will be playing this thing (though none are rock-solid confirms yet).
Foo Fighters, by the way, are out of the running to be a headliner. They're going to be in Australia over Coachella weekend. I have a feeling the headliners will come from this list: R.E.M., Beastie Boys, White Stripes, Oasis, Green Day, No Doubt (reunion), Smashing Pumpkins.