After playing with WA for a while it seems to me that it is not so much a better search engine as it is a better encyclopedia. Many search results read like condensed Wikipedia articles.
Out of curiosity, where did you get the idea that it was intended to be a search engine?
From thousands of articles saying it's a Google killer. And I guess I'm not the only one who got that idea, because Google search for "wolfram alpha search engine" returns over 600.000 hits.