Correct me if I am missing a thread on this already ...
Yesterday, started to see a faint header/menu on Google that was different than before -- light grey and almost AdWords'esque, rather than just white space, with a "Sign in" link and "Search settings/iGoogle/Privacy" dropdown on the far right.
Today, I am seeing a slightly larger font size used for the URL of each result -- probably just a point or two bigger, but definitely noticeable. This applies to URL's for organic and paid results, as well as the source/author for news, video, etc.
The latter change interests me more than the former. Google obviously wants to make sure that you know what website you're visiting, but at the same time, those keyword rich domains (specifically the bolded text that comes along with it) are now even more eye-catching than before.