An alternative to fully shutting down the site would be to "freeze" it. The site is available, but nothing changes. (This could even happen 24 hours per day: updates only happen every 6 hours or something.)
To me, the alarmingly addictive thing about HN is that something interesting could happen at any time. Removing this real-time aspect, HN would still be interesting, but no more addictive than a good issue of the New Yorker or whatever.
I agree with that. Normally with newspapers there is nothing of interest to read after a certain amount of time spent reading. But on social news sites, an interesting article can appear anytime. It's basic operant conditioning. After a variable amount of time, you get the reinforcement of reading an interesting article. And the VR(variable reinforcement) schedule happens to be the most addictive. http://en.wikipedia.org/wiki/Reinforcement#Schedules_of_rein... And the Fixed Interval (FI) schedule, which sounds like what you are suggesting is also the least rewarding. So I think it's a great idea.
I was thinking that anyone can access the site and do anything that they would do now. The only difference is that what you do doesn't affect other people until the freeze interval is over.
Freezing the content of the main page to update at a fixed rate makes sense.
The comments won't work as well if they aren't done in real time in the current format. One possible solution would be to add a separate section for active comment threads. This might serve as an acceptable way to slow them down, or keep them visible longer. However, the real time comments are a large part of what makes this site addictive, but it's also what provides a fair amount of the value.
To me, the alarmingly addictive thing about HN is that something interesting could happen at any time. Removing this real-time aspect, HN would still be interesting, but no more addictive than a good issue of the New Yorker or whatever.