Well in 2002 they were pretty big but not close to what they are now. I find it interesting that RHCP has headlined 3 times since Foo Fighters have been to Coachella. The Foos are bound to happen, I'd say sooner than later.
My 4th Annual Coachelectro (Coachella 2015) Mix
Featuring 80 Acts Playing The Fest This Year In Just An Hour + Free Download
Jeez unless we get Bowie and Daft Punk the well has run dry
never headlined or played before but could:
The Rolling Stones
Played before and ready to upgrade to headliner:
Mumford and Sons
Played before and almost a headliner:
Could headline, but odd fit for the festival:
I would die of happiness if AC/DC headlined
Jack White & Friends
Missy Elliott & Friends
Sigur Ros (upgrade)
Eric Clapton (odd fit)
possible first time headliners...
Motley Crue reunion
Some shitty band I could care less about with some whining b as the singer
Some hippity hop act that again I could care less about (I respect rappers more than all techno 'beat makers')
a decent band that that couldn't draw 15,000 for their own show in their home town
Dip Set Reunion
Also Cut Copy WILL NEVER BE A HEADLINER.. and U2 won't headline anytime soon.
Will Pharrell William's hat make an appearance?
Bowie with guest appearance by Mick Jagger