Google has instituted what they're calling Universal Search. What this means is that when you enter a query into the main Google Searh box, you get results from all over the Google empire -- Web Search, Image Search, Blog Search, News Search, Google Maps, you name it. If the result is relevant, it shows up on the results page. (Which means you might not see results from all the search sites; if you enter an address, or example, you'll get Web and Maps results, but probably not News and Image results.) You can filter your search results by clicking the appropriate link (Web, Blog, Image, etc.) in the information bar at the top of the results.
Universal Search is kind of cool, in that it puts all your results in one place; you don't have to jump from one part of Google to another to see the results. It's also relatively transparent, which is good.