Already, there is interesting potential competition for Google.
There's Teoma (www.teoma.com), for example, which uses the existence of subject-based communities to home in on an answer to a search query. Then there's Mooter (www.mooter.com), which uses ideas from psychology, software and neural networks to create a ranking algorithm that learns from the user as a search progresses.
And there are several research efforts aimed at finding ways of searching the "deep Web" -- that is the huge reserve of documents buried in corporate and official databases which only become published Web pages if a particular search query asks for them.
Furthermore, of course, there is Microsoft. There is always Microsoft. Bill Gates has made it clear that he sees searching as Microsoft's business.
The company has a huge research and development effort devoted to it.
And it plans to use its, er, "infrastructural advantage" [monopoly] to build natural language searching into "Longhorn" -- the next release of its operating system, due next year or 2006.
RSS