If Google is planning to roll-out such ads to a bigger audience, it might have to turn off the "Links" feature of Youtube. Here's why ?
Youtube has a "feature" that shows which websites are linking to a particular video and how many clicks originated from that site.
If you look at the screenshot below, the first site that's linking to this Youtube Video is the same site that's serving the Adsense Ad. Hence the "8590 clicks" are actually Adsense clicks originating from sites where the video was shown via Google Adsense.
This is the full URL:
http://gmodules.com/ig/ifr?url= http://www.labpixies.com/gadgads/gmail/gmail.xml&up_clickurl =http://pagead2.googles..
If the Youtube Links feature is left untouched, it might give fairly good idea about video campaigns that become popular among users on sites that have Adsense.