Is this an old news or just in? I have been browsing a premium publisher's website when I noticed that "ads by google" is not attached to the ads!
Premium publishers are allowed to have different formats, but they need to be approved before running. You need millions of page views a month to qualify.
This is news to me as well, only changes I can make to the ads is the color variations and recently introduced font size and font family to match my site!