I went to see A Silver Mt. Zion a couple years ago and there was a part when Effrim said people could ask questions. Someone asked "What happened to Godspeed?" The reply was, "Godspeed is now known as The Arcade Fire"
I have a hard time imagining that Godspeed would play Coachella, although there are very few bands I would rather see. Their performances seem to be so dependent on the atmosphere - they gravitate towards unconventional venues, and they utilize film projections that I can't imagine they would be able to set up at Coachella (I mean, Sigur Ros had to do their set last year sans all their standard visual enhancements). Plus, aren't they Communists? I would imagine that they would probably balk at doing a festival that - and this is not something I'm complaining about - is so heavy on corporate sponsorship.
However, I bet they could be a prime-time main stage act if they ever did come out of hibernation.