I run almost the exact same specs are you and kalih

Q6660
4gb memory (3.25 due to XP's cap)
XFX 8800GT
2 22" Monitors

I run 5 instances of WoW with no problems. My single GT powers the two monitors at 3360x1050 (in horizontal span), just fine, and the only hiccups (really, sub 50fps -- which is my cap) is when first loading the bajiliion people in org, and I'll drop into the 20s there. All in all, very playable, and you shoudl be fine.