The first half of 2009 has seen some pretty strong adjustments to search-engine technology. The introduction of a new engine that assists and assembles scientific data: WolframAlpha.com. A rebranding of Microsoft’s search product into Bing (see article), which bills itself as a "decision engine."
Yahoo held an entire event focused on how they’re leveraging their multiple search products to decipher user intent. Google has products in Google Labs with new presentation formats (and new ways to help them understand their users).