http://www.youtube.com/watch?v=Yf4pJ2F8MGY
Watch it, and tell me that doesn't look fun? It's freedom. Some players basically decided to claim a cave theirs, keep some of their stuff there, and some other players decided to raid it. Was there a no fire zone there? Did they have "challenge" them? No. Players create the world.
If you also look on their forums you will notice there are "gangs" or groups of players that stick together. They fight other groups. It's exciting. Basically what I am saying here is, learn from this mod. Let the players make the world. Anyways, comment and tell me what you think.