I'm not sure I understand what Wolfram|Alpha is yet, but so far it's pretty impressive. Developed by Stephen Wolfram and his team, it claims to be a "computational knowledge engine". The input box looks like a search engine, but it is definitely NOT a search engine.
When you type in a question, it attempts to show you all of the relevant data it can find. It is actually calculating and charting this information real-time in order to present it to you. Because its built on top of the Mathematica Engine, it can also handle math problems.
I think this will be an important tool for many designers of infographics, because you can get some of your raw data directly from Wolfram|Alpha. As they add more data into the system over time, this will become one of your best resources for information. They have a pretty extensive page of examples by category that is a great place to start. Also watch the short video by Stephen Wolfram showing what the system can do.