A Google search today brought up an unexpected prompt. I am used to seeing the alternative spelling prompt ‘Did you mean’ at the top of the page and equally the ‘Dissatisfied? Help us Improve’ link at the bottom of the page.
However, on a search for Hillsborough after the fifth result was a thin blue dividing line with "Dissatisfied? See results for: hillsborough disaster" below. This was followed by further results below this and is the first time I have seen results displayed in this way.

This appears to be a way of associating related terms, so if you chose one term ‘Gin’ it is prompting you to search for the associated ‘Gin and Tonic’ as a way of narrowing your search and improving your search results.
Google often experiment with their search engine results page below the radar before making announcements about changes. Could this form of predictive search be another example of one such experiment in the offing?
As ever, a quick search reveals that a small section of the Blogosphere has picked up on this as well, although many people are unable to replicate the results suggesting this may be a localised experiment for now.