well you cant upgrade your RAM without upgrading the mobo (except just getting faster RAM), so i think it would be better to just save up some cash and slowly upgrade your rig... upgrade your board and RAM next, then grab a new CPU and then you'll need a new PSU of course, then you can get an even newer GPU, then this that and the other thing
Got the 8600GT today and it is amazing, I really appreciate the recommendation.
I am able to play CoD4 in max settings 1600x1200 with decent 30ish FPS, awesome ;0
Command and Conquer 3 is the only other game I am really playing at the moment. But yeah not sure if I will make use of the SLI at the moment, doesn't seem necessary for my current needs.