Google is bringing in Google Certified Ad Networks, a new feature which will allow non-Adwords advertisers to compete with Adwords for your Adsense unit, which means the higher paying ad will be displayed, and this means more revenue for Adsense publishers.
This video explains all about the basic concept of Google Certified Ad Networks
All these participating ad networks will be certified for adherence to Google standards for user privacy, ad quality, and speed. Publishers will have an option to opt out of receiving ads from specific networks, or all networks completely.
Either way, just like enabling image ads (which also enables flash ads, video ads), third party ads, and placement targeting increases ad space competition, displaying the highest paying ads, and increasing Adsense earnings – these Google certified ad networks will be a promising additon for Adsense publishers.
Dont go looking for the feature just now – it will be rolled out first to publishers in North America and Europe followed by rest of the world.