Google revealed the share of revenue awarded to publishers for the first time ever. The amount paid to publishers who run "Ads by Google" ads is 68%. AdSense for search publishers get 51 percent of that revenue. Google says that their higher take on Search ads is due to the "research and development involved in building and enhancing our core search and AdWords technologies."
Normally publishers have a fairly clear idea of how much they will be paid for running ads. Until now, Google has never disclosed that percentage, which has caused frustration with publishers.
Google also commented that it cannot say at this time how much profit the company makes from this service--as it is still trying to calculate the costs of the service to deliver those types of ads.
Apple announced a 60-40 revenue split with web developers and publishers on its iAds program during the iPhoneOS event in April 2010. Google is obviously trying to show that they give publishers a larger cut of the pie.