A lot of forums (EVE Online's for instance) have an auto thread lock feature after 90 days of inactivity. If no one has anything to say about something after three months, I think it's dead, JimUnless you're a professional necro or something, most are inadvertant, say if you're using search, and forget to check the dates before adding your two cents.
Anyway, I'm not sure anyone is so necro-friendly (or should that be necro-curious?:0) that this would actually be a problem. What does everyone think?