Google rolled out an experimental new search architecture called Caffeine earlier this week, and while the differences in results between Caffeine and traditional Google are subtle, they're there. Get a side-by-side view of results from both Google engines at Google Caffeine Compare.
(Click the images for a closer look.)
After a few searches between Caffeine and Google Classic, the Caffeine results have—for the most part, at least—seemed slightly better. By better, I'm talking more relevant to what we were looking for when searching—though, in fact, on many searches the two were nearly indistinguishable in the first few results returned. Let's hear more specifics on how the results compare for you in the comments.