After recently announcing a partnership between Google & Viacom, their new video ads have begun displaying for a small group of specially chosen publishers. The videos, which run clips from a variety of shows from Comedy Central, MTV, MTV2, The N, and Nickelodeon channels, are interspersed with ads, and publishers are paid on a CPM basis on how many of the ads are viewed by the user.
For more information on this limited pilot from AdSense, see detailed writeups at both JenSense and SERoundtable.