I posted the following thread in the Sony Vegas forum last night but thought I'd post it over here too since some of you wedding guys may not visit that section as often. If you have a moment to take a look, I'd appreciate it! I didn't want to duplicate the post here in the wedding/event forum so I'll just link you over to it.

http://www.dvinfo.net/forum/what-happens-vegas/525252-need-help-dark-grainy-footage.html

Some gamma correction (curves or otherwise) + some Neat Video noise reduction and you should be OK.

Neat Video works great to clear up grain. Then adjust White Balance or Color Curves etc.. I don't use Vegas (Premiere user) but some of these have Auto Settings which works pretty well. Try Auto White Balance, Auto Color Correction etc. Should get it pretty good, then myb add another color adjustment for final tweaking.