According to the blog,
Leaderboard (728x90): the title, description, and URL are now arranged in rows instead of columns (except in the case when only one ad is showing)
Medium and large rectangles (300x250, 336x280): the URL is now in the same line as the title
Hoe these changes can help the publishers.
Source: http://adsense.blogspot.com/2010/08/new-look-for-adsense-for-content-ad.html
Source: http://adsense.blogspot.com/2010/08/new-look-for-adsense-for-content-ad.html