End to the passive-aggressive hellbans and service degradations (e.g. slowban, rankban) for obviously non-spamming users.
Re-show comment karma in order to restore trust, in the wake of awareness of rankbanning, since that will provide transparency in comment placement.
Hacker News still has a community advantage. (I'll take HN's irritating-- but at least book-smart-- libertarian naifs over the actual idiots of most forums any day). The moderation could use some work, though.