As the title said, Google AdSense for Feed will be discontinued. Effective from December 3, 2012.
Following is the email from Google team.
We’re contacting you because you’ve enabled AdSense for feeds in your AdSense account. After carefully evaluating the product, we’ve decided to retire AdSense for feeds.
Starting December 3, 2012, we’ll discontinue serving ads via AdSense for feeds on RSS feeds and you’ll no longer see feed units in your My ads tab. To check if you’re currently generating any revenue from AdSense for feeds, visit your “Products” performance report and look for recent data for “AdSense for feeds”.
Please note that reporting on your feed ad units will remain available following the product retirement. FeedBurner URLs powered by Google will continue to function, but will no longer serve ads. As a result, it won’t be necessary to redirect your subscribers to different URLs or to take any other action in your account. For more details please visit the AdSense Help Center.
Rest assured, this upcoming change won’t affect the availability of other AdSense products that you’re currently using.
We appreciate your understanding and thank you for your patience as we continue to develop new features and offerings within AdSense.
The Google AdSense Team