Google is testing a new look for their search results page designed to increase functionality, as well as add some "eye candy". The major change that is immediately visible to users is the new "navigation bar" at the top of the screen. By default, this has links to Google Web, Image, and Video searches, as well as Google News, Mail and a "More" button. The standard account management links are still at the top right, although "Search History" has changed to "Web History" because of Google's recently implemented web tracking.
There are also other minor changes, such as the change from "center" alignment to "left justified" in some sections, and the search results number + speed indicator moving to the bottom of the page.
These new changes, althought they add little loading time to the page, increase the visiblity of the various Google services. They also genuinely help users to find the information they are searching for by presenting more of the available options on the screen. Let's hope Google continues to make changes for the better like this with it's other products.