Perhaps one day we might see the forums leave its seemingly perpetual state of beta(ness?). On that day, I hope to see this feature included... Wait for it:
AUTOMATICALLY LOCKING THREADS
People keep necroing ancient threads for no good reason! Perhaps to push a novel pickup request or maybe to say a word or two ('lol' is a frequent culprit). These things either do not need to be said or people can make new threads! That's what the button's there for, people! START A DISCUSSION, don't revive one that's been dead for months!
So anyway, please consider adding self-locking threads (perhaps locking after a few months) as a feature if we do ever leave beta?