Have read some articles, commenting on this, generally negative, have tried it myself and I don’t see the point. It is based on some internal databases, therefore the information is not live, unlike Google who does a full WWW compilation every day.
Apart from that, the more typical answer is “Wolfram|Alpha isn’t sure what to do with your input”.
The times were it “replies” something meaningful, I don’t see any added value, vis-a-vis, e.g. Google. Taking the example in this article, this is the first link on Google:
WikiAnswers - When did Adolf Hitler die
Germany in WW2 question: When did Adolf Hitler die? Adolf Hitler died on the 30th April 1945. In his underground bunker in Berlin, Hitler realized the …
What Google gives us are a lot more choices, while Wolfram just presents whatever info it contains on its no realtime databases, usually with a single answer.
As I said, I don’t see the point. Google (the only search engine I usually use) is getting smarter and smarter. The times where the information returned would be very difficult to use are gone. Nowadays, if there’s information on the Internet, pertaining to the info I’m searching for, I always get it on the first hit results page. And most of the time, the info I’m searching for is contained on the very first results.
Google is the King, Wolfram hardly a peasant.