WolframAlpha should be available within a couple of weeks. From the demos I have seen, I am very impressed by it. No doubt it will take some time to iron out the wrinkles but I am very much looking forward to it.
There's been a lot of hype about wolframalpha displacing google but I think that's a misrepresentation. Google is a great search engine that is designed to find sites for you that MAY have the information you're looking for. Its success depends on how well you phrase your search and the extent to which the site loads keywords, i.e. it is a hit and miss prospect.
Wolframalpha, on the other hand, is intended to provide you directly with the information you seek. It's a completely different paradigm. The early design appears to be geared toward quantitative information (How tall is the Eiffel Tower? What is the longest river in the world?) which is a natural endeavor for the creator of Mathematica.
We'll have to wait and see how it evolves and whether it can cut it as a general information search engine. In any case, I can't wait to try it out!