Earlier today, Google rolled out a new feature for search to complement Google Instant, called Instant Previews. This new feature allows users to preview search results before they visit the actual page to see if the results are relevant.
However, Instant Previews is not yet available to everyone. If you are waiting to try out this new feature or just curious about it, you can visit http://www.google.com/webhp?esrch=instantpreviews to start using them. Instant previews in Google search can be viewed by clicking on the magnifying glass icon next to the search results.