I tried asking it some questions about the Amiga and all it responds with is:
"Wolfram|Alpha isn't sure what to do with your input."
It's shite.
I think some people are missing the point. It's not supposed to give you trivial information or return search results. Read the FAQ if you want to understand its purpose.
IMO the AI behind it is more exciting than the actual usefulness of it. Imagine what it could mean for human-computer interaction if the parser were developed to a sufficient level to accurately interpret spontaneous language, and the database were complex enough that the computer could make sense of, and respond appropriately to, whatever you say to it.