I know it has been a while since I posted an update, but here it is.
After a couple weeks of trial and error, I final developed a bookmarklet that I am happy with. If you are a FireFox user, I would strongly encourage upgrading your bookmarklet to the new one found in your homepage. The new bookmarklet, is faster and it can grab videos from private pages (ie. mySpace, Facebook).
Improve download algo
When viewing your bookmarked videos some will have the option for downloading. If downloading is available you will see a download link below the video. I have made some major improves to this feature.
Improve logic for detecting the flash video URL
You can download high quality flash and MP4 videos (YouTube only) when available.
Show all tags
When viewing your video collection you were only allow to view up to 50 tags. This resriction has been remove and you can view all tags by click on the 'show all tags' link located above your tags, enjoy!
Comments and rating (RIP)
I disabled this feature because it was rarely used.