A new experiment just goes public for AdSense to use Rounded corners instead of the classic squared corners. The new feature provides two flavors of rounded corners: slightly rounded and Very rounded. Of course if you don't opt for anyone the squared will be displayed by default. What I find interesting is that usually borders are annoying to make ads stick with content and generate very low CTR, now it's interesting to experiment the new ads especially with the rounded Google logo which fit very well with the new design.

AdSense goes web 2.0 with the new look, and it's the first contextual advertising program which started providing such new look for its ads. I think blogs concerned are mainly those with very web 2.0 designs and which usually don't generate much clicks. I have opted for very rounded corner just to test it, and thing that I didn't like is especially the text which is very close at the corner with very rounded corners, probably it's more interesting to experiment slightly rounded corners instead of the very rounded ones.