This represents several milestones in the game:
* introduction of submaps/subworlds -- no longer is the game restricted to one gigantic overworld, you can now go to different self container worlds, possibly hosted somewhere else
* introduction of the quest element, as opposed to random pillaging and exploration
I've also very much solidified the networking aspect of the game, so if you have a reasonable connection to the internet, the game should play fine.
Let me know what you guys think (and if you can kill the Rat King, whether or not he's too hard, etc.).