To let you know, I'm looking for answers that describe the atmosphere and functionality of Hacker News in addition to the appearance.
http://news.ycombinator.com/classic
As you can see, it's still not much different from the regular frontpage, which is encouraging.
The median comment is probably not as good as it was several years ago, nor as civil, but things aren't dramatically worse, partly because the sorting of comments (which I've tweaked a fair amount) means the lame ones are less visible.
HN traffic roughly doubles each year. That growth rate shows no sign of decreasing. If it continued we'd have 32x the traffic in 5 years. We currently get a bit over 80k unique visitors on a typical weekday. 32x that is 2.6 million. It seems overoptimistic to expect the site could grow to that size and still be bearable to use. So probably either the growth rate is going to have to decrease, or HN will be destroyed. I'll do my best to make sure it's not the latter.
Alternatively, would you take steps to limit new membership? HN these days is often mentioned in the same breath as Twitter, Reddit, and Digg by many bloggers. I don't see that trend stopping any time soon, so if you didn't plan on implementing subreddits, then something like this might be necessary.
The Eternal September phenomenon has always been fascinating to me, not least because it is one of the Internet's oldest problems, yet it remains unsolved. I'd be interested in reading your thoughts on how a community can protect itself from dilution in this manner. Beyond the ideas expressed in the following link, did you have any other thoughts? Has anything changed your mind in the past year?
My thought is that older cultures tend to be more formal as a means to effectively cope with the larger-than-150 community size of developed cities. I don't know how to apply that to the culture of an online community but I think that is where there is hope for effectively coping with the size of HN. This is the largest forum I have ever participated in. I know there are some other large forums out there, but I don't know how they compare, size/traffic-wise, to HN. In terms of culture, my general understanding is they tend to be less polite.
Where I think HN will need to change significantly is in the way submissions are handled. Currently you need a score of about 4 - 7 in the first hour to make the front page, as the number of users increase, the score threshold increases with it. HN is at the higher end in terms of front page quality, but there's already a lot of good stuff that gets missed. Ultimately that will be compounded as things go on unless something is done to cope with it.
For example, what if you could look at all postings that have at least 10 but fewer than 30 ups? What if you could look at the posts with the most ups of all time? A data-mining point of view might accentuate the depth of the knowledge represented here.