NeatVideo.com has introduced version 3 of their fantastic noise reduction application and plug in for various video editing systems.
Version 3 is available as a half price upgrade for most version 1 and 2 users; recent purchases of version 2 in 2011 may be eligible for an even greater discount. Contact them for information if you fall into that latter group.
From my first quick tests version 3, on my quad core editing system, seems to run about 4x faster than version 2. Prior to this upgrade, NeatVideo required almost an hour per minute of HD video. With version 3, this now runs in just over 15 minutes. Of course, for any lengthy video noise clean up, I let the process run overnight.
NeatVideo examines the noise characteristics of your camera (as reflected in a noise sample of the video) and uses that information to produce excellent noise reduction on most scenes. My own experience is that it works best on film-like grain, the very fine bits that dance around and are especially noticeable in dark areas or in broad areas of contant color (like the sky).
Most noise reduction techniques are primitive in comparison to NeatVideo. Most NR methods just average pixels together within a frame or between frames, which tends to reduce the resolution, turning images to a seemingly plastic look. NeatVideo does not work that way and does a far better job.
I have not used NeatVideo on high ISO (high video gain) images. I know that some use it this way and are pleased with the results. Regardless, if you need to clean up some image noise or, like me, you like clean video whenever possible, I very much recommend use of NeatVideo, with the caveat that for HD, in particular, a multi-core processor (and now supporting GPUs too) and plenty of time is needed for best results.
Usage suggestion: Because NeatVideo takes a lot of time, and editing can require cleaned up video clips to be re-rendered and cleaned up again, I do all my editing first. And then typically apply NeatVideo to the final video just prior to output.
If I only apply NeatVideo to selected short clips, I do not worry about this. But when lengthy clips or an entire video could use some cleanup, I apply NeatVideo as my very last step in the editing workflow, before I produce my output files.