Note: As of February 9, 2012 the video was not available via Youtube. I will monitor it's status and post when it comes back online.
Rodman777, a top class sumo robot builder in his own right, posted the 23rd All Japan Robot Sumo Tournament official video below. For those not familiar with robot sumo, Rodman is one of the key organizers of the Baltic Robot Sumo and European Robot League events, and competes regularly at RoboGames in the US.
In addition to designing competitive sumo robots, Rodman also builds humanoid robots with a sense of humor: