A Search Engine Watch Forums thread has a member stating he noticed Google began testing moving the AdWords ads (search ads) nearer to the free/organic listings. It is hard to describe, so I created a video below.
I illustrated how in Firefox, if you expand the width of your browser, Google will stop moving the ads to the right. However, in Safari, you can see how Google handled it in the past, by keeping the ads right aligned and shifting them over. Here is the video that explains it:
The first browser is Firefox, showing how it is more left aligned. The second browser is Safari, showing how they right align the ads.
Forum discussion at Search Engine Watch Forums.