I noticed the feature, but was a little thrown off by it, inthat it pulled up some old threads that I thought were no longer germaine. I guess what I mean by that is that threads frequently relate to each other during a block of time. Pulling one of three threads from a time period can create an illusion of concensus that may have been invalidated by the next thread. In a "true" search, all of the threads would likely have surfaced. An example would be the threads about Exanta, and the false hopes they raise every time they show up.
There is always something weird about someone finding an ancient thread and responding to it as if it had been posted yesterday. I think this might increase the chances of that. Of course, others may like that to happen.
I also noted that the associations are somewhat whimsical.
Best wishes,