To me, the thing that makes Hacker News, well, Hacker News is that the site is really simple, from a technology contraption point of view. It is controlled and shaped and molded (and whatever other verb you want to use) by us users (counting PG as, well, prime user?) and not shaped so much by arbitrary software constraints such as binning topics (putting in buckets). The touch to tuning this site has been light, with such adjustments as flagging and tuning the rise and fall of topics based on a variety of heuristics. Some tuning has been undone, such as color coding "most valued posters"

If anything, I would say if we were to change the site, the next experiment would be to put a greater collective downweight on titles or source sites if there is a strong local temporal grouping (glut within a timeframe) of those tags/keywords posted. Example: lots of facebook posts at one time then facebook posts drop off the front page a little faster than if there was only a small number of facebook posts. But even that, I'm not sold on this.