A new 64-bit version of the NeatVideo plug-in was just released for Vegas Pro 9. This is the best plug-in I've come across to reduce/eliminate video noise while retaining most of the sharpness in the original clip. This plug-in has saved my ass many many times, when I had to do run'n'gun shoots in badly lit environments. Definitely worth checking out.
Neat Video for Sony Vegas Pro 64-bit : $100 for the pro version : www.neatvideo.com
Neat Video for Sony Vegas Pro 64-bit : $100 for the pro version : www.neatvideo.com