You will have problems playing with that GPU. Upgrade to a 6770 or a 7770. If you can't because you need a lowprofile card the best you can do is a 6670. I will link you to all three. Good luck to you.
I ran the friends and family beta fine with some settings on medium or high with an athlon x2 5600, 4gb of ram, and an 8800 gts with 320 gb of vram. Mind you the framerates dipped a lot when there was a lot going on, but it was playable. Just that, playable. I actually am waiting on my mobo which is coming tomorrow to finish building my new rig.