Yes I'm using it.

I run two displays both @ 1920x1200. I currently use keyclone with one large 'main' and 4 smaller maximizer iwndows on the other monitor.

I get anywhere from 40-60fps in Dalaran on my main and my others are locked at 30fps each which they all sit at.

I can play Wintersgrasp with no graphics issues, I can ride all around Dalaran. Huge jump from my GTx280.