Very interesting tool to discover new video. It would be interesting see more options in how the videos are related. It could become a very useful tool to track viral content.My company Traackr (www.traackr.com) uses similar technique to find the most influential users on YouTube and other content sharing sites. Check it out: www.traackr.com/explore.
I am moderating all comments to weed out spam (there's a lot of it). Comments are usually approved within a day.