Pending Comments Update
To recap, pending comments are a feature we hope might mitigate or eliminate the nasty comment threads that sometimes occur on HN. It essentially turns HN into the sort of hard-moderated forum where comments have to be approved by moderators before being seen, except to make it more democratic (and less work for us), any user over some karma threshold can approve comments.
Since the implementation touches many parts of the code, and I am at this stage still the one who understands the HN code best, I was encouraged to write it before I left.
The plan from the beginning was to make it possible to turn pending comments on or off per thread. Since the simplest v1 was to have pending comments sitewide, I released it in that form first. That code didn't break, fortunately. The next day I finished making it work per thread. Or more precisely per item tree; a moderator can turn on pending comments for anything from the whole site to an individual comment.
When I announced pending comments I said the threshold for endorsing comments would be 1000 karma. Some people have been alarmed by that. But 1000 was nothing more than a plausible initial value of a variable meant to be tuned by the moderator. In fact, the threshold never was 1000 even at first; I set it to 500 in the first release. Maybe it will end up being 50. The only way to figure out what works is empirically.
Indeed, the only way to figure out if pending comments will work at all is empirically. The plan is for the moderator to experiment with turning pending comments on for individual threads. If that works, maybe after tuning the parameters he'll gradually expand to more and maybe eventually just turn on the feature sitewide. Or maybe that will never be necessary. Or maybe software will decide when to turn on pending comments.
Nor does the threshold for endorsing comments have to be karma. That was the obvious choice for a v1, but it would be easy to incorporate or substitute other things like account age or average comment score, or even introduce randomness.
It's impossible to predict exactly how pending comments will end up working, but one thing you can safely predict is that whatever happens with them won't ruin HN. The main moderator is extremely sensitive to the state of HN, and if something he did was making the site worse, he'd be quick to notice.