I have a Club-3D 6800u, and it clocked to 445/1260 with stock cooling. I've had it at 425/1200 for the past 18+ months, and it's still holding out with newer games. I just finished Serious Sam2 at 1600x1200, max settings, med AA, 8xAF.
I'll probably be getting the next 512Mb card from Nv in the New Year, and it looks like my AGP 6800U will still get a good price.
(unless Nv/ATi release AGP versions of their latest cards by then)