Earlier quoted context omitted.
Watson's defeat of top Jeopardy! players, while an impressive feat of natural language processing, is not as impressive as a defeat of a grand master, for one reason. The reason is that when multiple contestants know the correct response in Jeopardy!, it all comes down to reflexive timing. It's no surprise that a computer could buzz in faster than a human being, and there's no evidence that Watson knows more correct…
But you still give Watson too little credit here. You have typically 3s from when the "answer" is shown to when you can click the buzzer. So in 3s Watson has to go through all of its databases and semantic links and formulate the question, from an answer that often doesn't even make sense to probably half of the US population. That's pretty impressive.
Think of it this way: if you had a human standing in Watson's spot, with a monitor displaying Watson's suggested response, I don't think that human would perform as well against the other human contestants. Sure, Watson would often come up with the correct response while the clue was being spoken by the host, but the human would still have to buzz in when the light turns on. If you buzz in too early, you get locked out for something like a quarter of a second. Watson would still be extremely awesome technology, but I don't think a human with access to Watson's output would compete at anywhere near the level that Watson did in the video.