Google Instant Previews, is a new search feature that provides a graphic overview of a search result and highlights the most relevant sections, making finding the right page as quick and easy as flipping through a magazine. To use it, click once on the magnifying glass next to the title of any search result and a visual overview of the page will appear on the right. From there, hover your cursor over any other result to see a preview. Orange highlights indicate where highly relevant content on the page is, and text call outs show search terms in context.
Google says that they've "found that people who use Instant Previews are about 5% more likely to be satisfied with the results they click. The previews provide new ways to evaluate search results, making you more likely to find what you're looking for on the pages you visit."
Here're some details about how to make good use of the feature:
For those of you who've recently stopped using your mouse to search, now you can navigate to a result, hit the right arrow key to see the preview, and hit the down arrow key to keep browsing.
Here's a video showing Instant Previews in action:
Trt it over here