It looks like Google AdSense has launched a new ad code type for publishers named Auto ads. I don't have much information on this beta outside of this help document and this WebmasterWorld thread.
Now, you might think this is automobile related but I don't think it is. It seems like a method for Google to automatically place ads on your site without you having to do anything but add one piece of code to your page. It might pick the best location and type of ads based on your web site.
Google wrote "to set up Auto ads, you first choose which ad formats you'd like to show across your entire site. These will be your "global preferences" for Auto ads. You can select from a range of ad formats. You then copy and paste the ad code on each page that you want your selected ad formats to appear."
There is a new code set up that is required and it is unclear how well this will perform. But Google is letting you set up ways to track the performance including creating a custom groups o you can track it better. Then you can track it in the various AdSense performance reporting tools.
Google added:
Note that you only need to do this once per page. The ad code is the same for every page on every site where you want to show Auto ads. After you've pasted the ad code, you can still make changes to your Auto ads settings at any time without having to change the ad code.
Forum discussion at WebmasterWorld.