I made a simplified installation script for the OpenGL workaround.
This is NOT a solution, simply a workaround until NVidia gets their minds to actually fix this bug. This workaround gives me 30-60 fps on my GTX470. I hope it works for you as well. NVidia driver version 275.33

http://nwvault.ign.com/View.php?view=Other.Detail&id=208426&id=1500

Best Regards
Nick

Sorry, I found this thread first and put my main response there, but, simply put, this isn't working on my GTX 460. It still runs ridiculously slow.

Yeah that's all been wiped, can anyone post this information here? Game runs terrible (but playable) on my GTX470.

Hey
@hapexindustries

You shouldn't need this patch for your GTX470 any more. It has been fixed for me on my GTX470!
Try updating to the latest Nvidia drivers: http://www.nvidia.com/Download/index.aspx?lang=en-us

If this is your first time running Neverwinter Nights you should know that there is no workaround for the general NWN stutter. That has always been there and us a limitation in the engine. Reinstalling or cleaning out your override folder might help a tiny bit.

Best regards