Ionut Alex on Googlesystem has posted a little secret about Google Video —”If you add "&output=rss" to the URL of a search results page in Google Video, you get a RSS feed for that results.”
For example, if you search for "apple", the address of the search results page is http://video.google.com/videosearch?q=apple. Now append the output parameter and you'll get http://video.google.com/videosearch?q=apple&output=rss, a feed you can add to your favorite feed reader, so you can track the best videos about Apple. If your feed reader supports enclosures (like Google Reader, for example), you'll be able to play the video from the reader. Otherwise, you'll see a thumbnail and you can click on it to see the video.
You can also search for labels (tags) like this "label:matt cutts" and add the results to your feed reader, in case there's a new video created by Matt Cutts. As anyone can label videos, there's always the danger of spam labels, so not all the results will be accurate.
Labels can also be used to create rudimentary playlists: invent a long string like "videos from my favorite pop artists" and label your favorite videos. Then do a search for "label:videos from my favorite pop artists", add the output parameter and use the feed the way you want it.
Google Video shows on the homepage only the feeds for some sections (popular videos, music videos and others), but you should know that every search means a new feed.