What I find most interesting is that Youtube videos show up but I have yet to see any "Google Video" videos showing up. Anybody got an idea why?
Take a look at the Top 100 list at Google Video and then search for the title of any of them on Google search... You should see them appear in the SERPs then. Some that are popular on multiple sites like Google Video, YouTube, Myspace, etc. show several thumbnail images on the first page of the search results.