If it's a day ending in "y", then Google must be rolling out a new search feature. This one is called Instant Preview and the way it works is when you get search results you see a little magnifying glass next to the link. Click on it and you get a pop up screen shot of the site before you click on it. You also get raised and highlighted portions that pertain to your search term.
Interestingly, this is being played up by Google as a new thing and while it's new for Google, it's not really new. Ask.com had something called Binoculars way back in ought four. It was more primitive than Google's new feature but it was the same concept. Kind of reminds me of all the search engines that had Instant results before Google did.