We covered this on the mobile ad side about two months ago, where Google is testing showing an "ad" label on the AdWords ad, as opposed to the standard format of a different colored background and sponsored label.
Google is now testing this ad label on the desktop results. I don't see them myself but Brian Ussery on Google+ and Rubén on Twitter sent me pictures.
Here is an image of the new format for desktop AdWords ads:

As you can see, the ads kind of blend better into the organic listings but at the same time, the hot gold ad label does make it stand out. I assume Google can make that gold yellow color more gray over time to make it blend better. ;-)
Ruben explains how to opt into this test on his new blog.

Comments:
xoxo
11/05/2013 06:26 pm
they are blackhatters!
Durant Imboden
11/05/2013 06:55 pm
Looks like a good idea.
Soni Sharma
11/06/2013 08:27 am
Eye-catchy... Change is the law of universe... Lolz
Dave
11/06/2013 12:03 pm
This is giving a solid support to the Google intentions to gain more and more money through Adwords.
Gracious Store
11/06/2013 09:12 pm
Google has to do all they can to boost one of their larges source of income, adwords
Brijesh Bhalodia
11/16/2013 09:16 am
I personally think that Google will mix ads and organic result in next 5 years.
Spann
11/21/2013 05:37 am
The new Ad labels aren't on the Google product listings. I guess that's because they're not ads?