This is Nelson Lee from Google explaining the process:
It is a small step but important if it helps folks find your content. For more detailed information about how to create video sitemaps visit Google's Help page on creating video sitemaps.
I have to say the video implied it was easy but looking at the Help pages has caused me to wonder what the heck Nelson defines as easy. I'll take a closer look but I'm not sure that the video site map is intended for blog based users. If it is indeed for traditional web site programmers and developers then I would see it as a way to filter out independent content.
Not sure. I need more info.