Just read about a study (done by the folks at Truveo) claiming that Truveo had the most comprehensive video search results The study compared Truveo, Blinkx, Google Video, Microsoft Live Video Search and Yahoo! Video Search against a series of standard queries. I won't be suprised if the other search engines come out with studies claiming something different ... this simply illustrates that this market is still emerging, and much work needs to be done before a "Google" emerges in video search. 

Read more about this study at: http://www.finchannel.com/index.php?option=com_content&task=view&id=20464&Itemid=10.