These all seem like likely adds (i.e. I think they're all good fits). I know MGMT and Black Kids have been mentioned on here before, but the other two are getting a lot of hype as well. For anyone who hasn't heard of them:
Ravens & Chimes - Reisenbach Falls (kind of sound like Arcade Fire, or Islands, depending on the song - kinda)
MGMT - Oracular Spectacular (they borrow heavily from the Flaming Lips)
White Denim - Let's Talk About It (I've heard comparisons to the white stripes, but i dont really see it - they actually have a talented drummer, haha - no offense to meg)
Black Kids - im sure everyone's heard of these guys by now, but the EP is Wizard of Ahhs and is available for free on their website.