Originally, it sounded as though Wolfram|Alpha would be able to answer any question under the sun – and perhaps that is the eventual goal. For now, it seems as though Wolfram is capable of answering only Factual questions. In other words, unless there is an exact answer to your question, Wolfram cannot answer.
For example, type in Thomas Jefferson. You get a few dates and the fact that he was “head of state”. But it does not tell you that he was the President of the United States of America, nor that he wrote the Declaration of Independence.
Something cool to note is that there is a link at the bottom of the page that tells you where the information most likely came from. It says, “This list is intended as a guide to sources of further information.” Then it follows with, “The inclusion of an item in this list does not necessarily mean that its content was used as the basis for any specific Wolfram|Alpha result.” In other words, it seems like Wolfram Alpha checks a variety of the most respectable and accepted sources of knowledge to find the correct value.
Tell me more. This thing is cool and will only get cooler.
I am curious what will happen once there is too much information about a specific topic. How will it get organized on a page. A simple example of this is entering the names of 3 public companies:
Dell Citigroup johnson & johnson
It gives you quite a lot of information for that question. But it is still nowhere near the length of a long Wikipedia article. But what will happen when you ask it an extremely complex and convoluted question? Will it spit out a 100,000 line answer that your browser will barely be able to load? Or will it find some beautiful way to organize the information?
Tell me more, please.