I was poking around in the network settings in DoubleClick DFP earlier and noticed an ‘Enable AdSense Integration (beta)‘ feature available. To my shame, I have no clue for how long this had been made visible and sits in the DoubleClick DFP interface, but there was no announcement or update from DoubleClick in regard to it.
Here’s a screenshot of the feature:
I have asked DoubleClick support for details on the subject (is it available in closed beta, and if so how would one work it since I haven’t found any way to add an AdSense publisher ID or code?). The answer came back very quick and… the feature should not be visible in the user interface yet 
Guess the wheels started moving and we can soon have AdSense as an option for the remnant inventory: nice move from Google who will then have access to premium ad slots and expand their content network to major publishers and placements.
September 4th, 2008 at 9:28 pm
This feature was taken out of beta at the beginning of September and is now being touted as an official feature in DFP. AdSense is not integrated with the DoubleClick Ad Exchange (it’s a separate module) and is being positioned as less effective monetization option than the exchange.