I've just been testing out Lexxe, a natural language search engine that's currently in Alpha. It claims to be "50% more accurate and relevant than any other search engines. [sic]" I conducted a variety of searches and although Lexxe delivered correct answers some of the time, I wasn't exactly blown away. From the Lexxe Technology page:
Lexxe is a third generation Internet search engine featuring Natural Language Processing technologies. It is fully automatic without human editing involved. Most of its answers come from unstructured texts and webpages on the Internet.
Lexxe departs from the symbolic computing methods of the second generation search engines peaked by Google, to the linguistic computing methods. In other words, acknowledging the fact that search is a language-oriented (or even meaning-driven) computing activity marks a paradigmatic shift and generation watershed in search engine evolution.
I can see why some companies are pushing NLP - most users don't know how to create good search queries and NLP offers a possible solution. It's Ask Jeeves all over again. But up until now no-one has been able to topple the 800 pound gorilla. And if this is the best that a "third generation" search engine can do, I don't think Google has anything to fear.