With recent talk about topic ownership and the likes, apoctr's comment here made me think of a possible mechanic that could be added:
Topics that mark specific points in time on Tildes or that are very popular and people keep going back to (like Petril's Where are you from? topic) it might be a neat thing to "disassociate" the topic from the author in case (or when) they delete their account (and subsequently all their topics) so that it doesn't just disappear and that little piece of history is gone. These topics could be given a special status allowing certain people to edit it and keep it up to date, maybe?
What do people think of this? Do you see any immediate problems with it? Are there any other sites that do this kind of thing?
Edit: after some comments the best thing would be as Deimos suggested here, having a wiki and posting the useful resources there too.