I am also using Win 7 for my new rig. In order to get the ASUS utilities to load I had to use compatability mode (compatable to Vista). That worked. I am also now using the NVIDIA 8171 driver for Win 7 and it loaded and runs fine. There have been no graphics issues at all.
My only issue so far is mt Temps. With a Zalman 9900 and only OCing to 3.3 Ghza I am getting temps at or near 50 C on all cores. I have reset the cooler and in fact I have a new one comming in tomorrow just to see if perhaps there is an issue with this one. I know liquid cooling would be somewhat better but 50 C is no better than a stock cooler.