Very interesting link.
I just wonder if the one bit of intelligence google is overlooking is the user. My experience is that 10 years ago if a user was looking for a job, they would type in "Jobs". Now they do far more sophisticated searches because they understand the way search works a bit more, and type in, "part time shop assistant job in Plymouth".
Using Amit Singhal's own example, "Taj Mahal", if a user wants the restaurant around the corner, surely they now understand that they need to put in "Taj Mahal restaurant in Ascot" or else they may get the temple in India.
It begs the question, why put all this effort into trying to guess what people may want or need from minimal information, when you could just give them a better understanding of how the current search systems work, and encourage users to define their search a bit better.
I suspect that this is all about providing the actual information you are looking for in considerable depth on the google search page..... disguised as 'improving the search experience'. If they succeed, many sites will never need to be visited at all. If you do the "Taj Mahal" search, the knowledge box tells you the height, phone number, architect etc etc which probably is what many people are initially looking for. The result will be that web masters who currently produce fascinating websites will never get visited, and they will just give up.
The danger for google is that they are straying into turning their search results pages into topic information pages. Is that what the users really want?