David Krane posted that Google Video launched a new feature named Movers & Shakers. The Movers & Shakers feature is a page that shows you the most popular videos at Google Video. You can filter by which videos are most popular by country.
Currently the most popular video in the world at Google Video is 2001 Japanese Tetris Finals . But let's see what is the most popular video in Japan. You would think it would be the 2001 Japanese Tetris Finals but no, it is Cool TAK - I am so cool.
Postscript: Wanted to clarify this a bit more. Movers & Shakers are videos that are quickly rising in popularity. Today's Movers & Shakers could be tomorrow's Top 100. Movers & Shakers is one way to identify videos that are becoming viral. Google uses algorithms to identify videos that are suddenly becoming popular, and then rank them based on how popular they are and how suddenly they became popular.