Relevancy is relative. It is about the intent of the user, first of all. What is the user trying to do? Then, secondly, what do you know about the user or the query that could help to better refine the results?I disagree with the above statement. By definition, a document is relevant if it satisfies a user's "information need". I think he's really trying to say that too often we make the mistake of removing the user from the equation and creating a universal relevance judgment that holds across all users who issue a query.
The interview goes on to talk about how Microsoft is investing in technologies to support complex decision making, in vertical categories like travel, health, and shopping. He highlights Farecast. However, it's also clear by the current Bing results for plan a trip to Florida, that there is still a long way to go.
The article goes on to detail Microsoft's "vertical" strategy as a means of differentiation:
We will continue to introduce these verticals, in pretty short order, frankly. The sum of those parts will become a very differentiated experience that will expand how people think about search...If you missed it, yesterday Microsoft started rolling out Bing Recipe Search.