Dude, indeed. I was totally impressed just moving from two 6850s to a GTX 480 (and the crossfire setup is technically a bit more powerful). In addition to the big IQ improvement from going to 4x MSAA from 2x (mainly on long distance views) I also noticed all kinds of smoke and dust and other effects in places that just wasn't really there before. This 7950 should be like night and day for you; whole new game.
Don't screw around with FXAA in BF3 by the way; it just blurs the whole image. You can handle 4x MSAA with a 7950 at your res for sure, if not 8x.
“i dont care what consoles have they dont have mouse and keyboard” -crazyeyesreaper