Part of the fun of it is that this is an application that still requires one of the biggest computers that anyone on the planet can build:
Well the body of Watson, which is not on camera, is like 10 huge refrigerators, in an air-conditioned room.... Watson has the power of a couple thousand laptops working together.
On the down side, it's not a particularly elegant machine:
Instead of just trying one approach, saying 'We're going to do it statistically' or 'We're going to teach the computer a million different rules about the world,' IBM just tried a very pragmatic approach, which said that if there's anything that works, we're going to include it in this. So they've got hundreds of different algorithms all trying a different approach to understanding the clue and trying to figure out the answer. And then it's up to the computer to look at thousands of different candidate answers and pick out the one that's most likely to be right.