It's Buranovskiye Babushki, the "Buranovo Grannies" singing Party for Everybody for Russia.
So, yeah, it's a bunch of grannies (literally) from Udmurtia, a tiny region of Russia that has its own language. They're best known in Russia for covering western pop songs, and have parlayed an appearance on a Russian cultural news show into something of a real following. In 2010 they entered a more... traditional song, and came in third.
The video is the selection contest video. Normally I'm less than enthralled by that, but in this case we get audience reactions.
I like this one.
