Working great on my setup too
No problems with Doom3, Halo, UT2004, COD, NFSU, NFSU2 demo.
Flatout demo still crashes however. I blame the demo, not the drivers.
Also, the 66.93 drivers have the best 2D/3D IQ I have ever seen of any driver to date. Also, my 3D Mark 2005 score rose to 1300 using these drivers.