I would try to catch these artists if I was to go (if I got an unexpected promotion at work with a big bonus or won a trip to the fest):
Broken Bells, Bryan Ferry, the Afghan Whigs, the Cult, GOAT, Dum Dum Girls, Wye Oak, Crosses, MGMT, Mogwai, Warpaint, Future Islands, White Lies, Blood Orange, Beck, Neutral Milk Hotel, Fishbone, AlunaGeorge, Superchunk, Daughter, Surfer Blood, Aeroplane, Ratking
Wow, that list was a lot shorter than I thought it would be.