Forget your Dirty Projectors (although I have to say I'm fucking loving that album now) and your Grizzly Bears-- the best band right now is the PS22 Chorus. I first learned about them when this video of them covering "Eye of the Tiger" was posted on a bunch of blogs.
They're a fifth grade chorus in the Bronx apparently. Read more here: http://ps22chorus.blogspot.com/
Apparently Perez Hilton has been all over this and they've made various tv appearances and were part of American Idol 3 last year, so I'm late to the game on this. But recently their videos (esp. the one above and the Lady Gaga one) have been going semi-viral and making the rounds. And the're all amazing! Little Kids + Two Part Harmony + Passionate Singing + Cavernous Auditorium Reverb + Ponytail = Magic!
A selection of favorites:
Viva La Vida
Don't Stop Believin'
And holy shit, I'll Be Your Mirror! Gorgeous!
I'll Be Your Mirror: