Google has redesigned their ads to, as they say, “to improve the look and feel of our advertisements”. I can only see one advantage at this change and that is the “Ads by Google” text movement from above to below the ads. Now the visitor doesn’t notice that fast that those are ads and he may click.
Also, Google states that those new types of ads perform better both for Advertisers and Publishers, but i wonder how could they perform better for both ? A publisher wants as many as possible visitors to click it’s ads, he doesn’t care if they are interested in them or not, while the advertiser wants only targeted visitors, interesting in what he offers on his website.
Fortunately, they haven’t changed the fonts and, they say, colors, but they couldn’t have, becase the colors are chosen from the Google Adsense account by the publisher.
Here’s an example of the old and new ads:
And here is the official announcement from Google.

April 17th, 2007 at 12:57 pm
In new style, the Google word is much more prominent. And I think it will make visitors an impressions of “These are just ads”. Maybe i’m wrong. I don’t do adsense