Although perhaps not plausible it would be cool if there was an option to allow for a post/thread to be edited by the community a large, like Wikipedia. Some examples of where this would be helpful are the new release listing thread (which consists on community posts about releases then relies on one to hooefully edit the original post) or a genre listing thread categorizing all, for example, RPGs. I compiled a RPG listing thread and would. It mind community editing. In these cases if the original poster disappears the threads are in limbo unless community editing is allowed. Consider it. Edit: it's not that members are doing a poor job of maintaining posts, it's just the potential for such; plus this would enhance "community" spirit.
I've thought about something like this before, too. I would like to see a post in which you can add who can edit it, so maybe 2 or 3 people could work together to complete a list. If everyone was able to edit, it'd just turn into a mess with a lot of trolling.