I just noticed this last night, so I figure that those of us that don't visit the tech threads may have missed it. On my rig the improvements were not too noticeable, but they may be on yours. Remember to back up your system first.

http://news.bigdownload.com/2010/10/26/fallout-new-vegas-civ-v-and-more-games-get-boosted-with-new-nvi/#comments

Yeah, I ran the update on mine yesterday, not that I had been having problems so I don't see any difference - yet.