Computers beat humans at Jeopardy

The supercomputer “Watson” plays jeopardy. The box at the bottom shows three possible answers Watson came up with and its confidence (in percent) in each one of them.
Quite an impressive feat: An IBM-built supercomputer won against two humans playing Jeopardy. Note that the questions were not typed into the computer, it had to understand them when spoken. This shows that much progress has been made in natural language processing, but it still has to be a limited domain, where, I assume, questions follow certain patterns. Engadget has details and a video.
There is a HAL-like animation on the screen of the computer (which is even mentioned in the Wikipedia article on HAL). As an aside, what acronym do you get if you advance each letter of HAL one position in the alphabet? This has been rumored to be the source of the name, which has since been denied by the author.