Some co-workers just came back from the SES in San Jose and one thing that they said that made me take notice was how much the search engines were pushing verticals.
Now before I get too far I should mention that what you and I may consider vertical isn't necessarily what they consider vertical.
For example, I consider verticals to be industry specific, i.e. a legal search engine dedicated to legal services, or a travel search for travelers. But search engines have expanded this definition and are moving in a new direction.