I'm not saying it's a good idea at all, hate on it all you like. The longer I take to type this the less I care to back up the idea but here it goes.
End of the world everyone who is online is teleported to one select place on the map, possibly one with few trees/mountains etc where they are all left to their own devices. This being the end of the world will no doubt turn into a massive server-wide blood bath. Just a thought.