Google Categories?

Okay, I think I've got the scoop on this one. Google seems to be testing an enhanced "Did you mean" feature. Today I searched for "software developers", and it gave me a few popular categories to choose from (see above). The feature is sporadic; it comes and goes. Earlier this morning it worked for several searches, but minutes later the entire thing disappeared. In the above example, clicking on "software development companies" yielded more detailed categories (including "application development companies"). Clicking on "something else" resulted in a new search with negative keywords based on the categories I rejected. Sweet! But there's actually a bigger thing going on here. In order for Google to create meaningful categories, their system needs to understand concepts, not just keywords. In the past, Google's results have actually been quite dumb--they have relied on things like PageRank to determine which keyword matches are most useful. This is very different. They seem to be developing algorithms that understand higher level concepts. This path quickly gets into the monumentally difficult problem of artificial intelligence (AI).