With increasing numbers of people throwing out their bulky old CRT monitors and switching to large flat screen monitors with their increased resolutions, this is a very welcome change to the search engine results page (SERP) layout on Google.
It only seems to be a test at this stage as it only shows for me in Firefox 3 and not in Internet Explorer 8. A colleague of mine cannot see the change at all in either browser. Take a look at the two screenshots below (full size images at the bottom of this post).