I'm currently developing an application that takes web videos and converts them to the format of your choosing. You can select a file or just enter in the YouTube URL, it figures it out. I'll keep your posted.
I just bought the moyea.com flv-to-avi converter, works great... remember to go into settings and choose mpg2 (highest res) as output format, the default is youtubeish lower res... it's a very good program, does batch conversions etc..
For someone who often needs to work with converted SWF files in Vegas I can also recommend Moyeas SWF to Video converter. After I tested many SWF conversion apps this was the only one which had no problems preserving transparancy correctly in all the files I used. In my opinion they provide a real good toolset whatever you may need out of it.