If your really impatient get the 8800GTS if your more patient then wait for the ATI cards. The ATI cards will lower the price of the Nvidia ones if nothing else. right now an E6600 and a 8800GTS would make an awsome rig. I say go for it. You should also get the eVGA nForce 680i, it'll let you upgrade your CPU to quad core in the future. Get some good DDR2 800 ram, and a nice Full ATX case. and you'll be off to the races. of course you'll also need HDD, optical drives, etc.
EDIT: just make sure the first thing you do, if you get that mobo, is update the bios.