Today I'm seeing a three column layout. Left column is search options, center is the the serps, right is adwords ads.
When the cursor hovers over a result a box with two right pointing arrows appears. If the cursor hovers over the box, adwords is replaced by a large site preview. Scrolling down the results with the cursor in line with where the boxes appear keeps the previews active, adwords does not reappear until the cursor is moved from that line.