Thanks Fenril.

I will give disabling SLI and reverting drivers another try before I bust out the cash for GTX580. I tried disabling SLI before. Didn't really improve anything, nor degrade anything. So I figure I just left it on. It was just my wishful thinking that one day, all of sudden, WOW would support SLI fully. and with both card running at 90-100%, the game would perform well. and it really bothers me to have my GTX 295 is running as a GTX 260, lol.