This first implementation of the overworld doesn't include many features, mainly existing colonies and gameplay have been converted to work in the new overworld map. The main reasons for this change were due to BYOND's billion limitations, between map size and processing power limitations. Having instanced colonies will allow for a larger overall world, and allow for AI that's actually being used to be handled more functionally and efficiently.
Though it wasn't intended, this has actually given a lot more direction to the gameplay plans. I have been trying to decide how I wanted random survivors, campsites, story sets, and other events to appear around the game. With this new overworld map mode, it solves all of those problems, and also gave a bit more functionality to colonies. In future, players will be able to choose a main faction, and siege player (and NPC) built colonies for global control. It should all work a bit like Mount & Blade's singleplayer.
Apparently, editing a post will remove it?
Its on the to-do list as a dungeon boss