I would agree. I've been a lurker on HN for a couple years and the recent PG post about creating wealth was new to me. It was a wonderful post, old as it may be, and much more useful to me (a developer) than multiple posts about another acquisition.

Can old links be re-posted after a certain period of time passes?

If so, maybe auto-add a prefix, "REPOST: Article Title", for any link that's re-submitted. That way people who've seen it before can ignore clicking on it, while those who haven't seen it will now have the opportunity to read it.

EDIT: BvS already posted a link to a Reddit post with the same idea.

I would prefer if anyone posting a link would append the year of the original article, regardless of whether it's a repost or not.

Apart from the current year (which is implied).

I agree with your points. The only thing that I would ask for is to date new submissions of old posts with a label such as [2004] so that readers can immediately grasp whether it is a new essay or an old one.

Essays, like good literature, become more relevant and certain times. A major event could happen (Groupon turning down Google) and a PG essay could shed some light on the situation, even if it was written years ago.

Likewise, new situations can cast a different light on what was once written. HNers posting relevant and timely links to old essays is a good thing.

I agree that the discussion, especially the questioning and answering (but not so much the posturing) is especially good.

But can we limit it to one resubmit per year? After a couple times in the same year, my patience grows thin. After all, HN has a lot of really good essayists out there, folks who can be just as helpful. As nice as PG is, we don't want to give him too much exposure. After a while anybody can start to sound repetitious, like when they go on and on about something. Sort of like repeating themselves. Over and over again. The same thing.

Gets annoying.