I hope you haven't yet bought this. You can do better by getting an X4 955 and putting the extra cash into a 6850, $130 after rebate: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102908
With those in the box, it'll run the most demanding modern games on high settings (Crysis 2, BF3; far from the highest settings, but quite pretty) and will max less-demanding ones (SC2, WoW). I consider maxing to be 60fps.
Ya, this is quite a decent build.