On the ‘Inside Adsense‘ blog, Google writer Arlene Lee states “After reviewing our AdSense video units feature, which allows you to show YouTube content and ads on your pages, we've found that it hasn't had the impact we had hoped for” and that they'll be terminating the program at the end of April.
Or, in other words, the Adsense for Video program hadn't made enough money for Google within the year it was running, so it gets the axe. Sounds about right — and I'd add that Google has a lot more patience than I, but they also have a lot more money to play with — mine included 🙂
The option to sign up for video units is no longer available to new publishers and if you currently display video units, Google recommends that you start removing the video unit code from your pages ASAP. Earnings from video units in the past will still be credited to your AdSense account until the end of April. At that time, any video units that remain on your sites will direct your visitors to YouTube – for which you won't get paid.