One other thing I would find interesting would be some questing. Not in classical way where you go to an npc an get a quest to do. But something which is persistent for a whole server, not for the individual player. I was thinking of random notes that you would find, maybe leading to special locations where you could hints to another special thing and so on. The notes would be persistent and found at dead players and every note or hint would be persistent on the server. I think this would open up possibilities for interesting stories to occure.