Henry Blodget poses some provocative search questions and gets a thoughtful answer from Walt Mossberg, who has switched from Google to Ask as his primary search tool.
This is significant as I recall that it was people like Mossberg, with a huge audience, who reported early and favorably on Google, creating the favorable buzz that launched them from obscurity to search stardom in just a few years (also less well known people like me and the thousands of other web savvy folks who helped with the positive Buzz about Google back in the ancient internet times c1998).
I don't think internet habits die all that hard which is why I have Google puts AND admire Google's brilliance at the same time. Online fortunes, literally and figuratively, can change overnight. Note that over a decade we saw Alta Vista, then Yahoo, and now Google as the 800 pound gorilla of search. The new game has Yahoo and Google equal in actual relevance (though not in perceived relevance) with Ask and MSN catching up soon.
All use different approaches and eventually there will probably be a "breakout application" that will do a much better job. As Jeremy Zawodny has noted people won't switch because you are a "little better". The next search giant may need to be "great". It might remain Google but it could also become, for example, IBM who arguably has the best but too-slow-for-prime-time search routine called "WebFountain".