I have just noticed this change on google.co.uk - the page preview is shown as soon as you put the mouse over the results (i.e. there is no need to click on magnifying glass as in google.com SERPS)
In fact, you do not even have to hover over the title of the result to see a preview - move your mouse anywhere in the central column where the results are and the whole result gets boxed in blue and the preview of the page is shown.
It also works if you hover over google places 7-pack
