Correct me if I'm wrong, but I am pretty sure Qwerty was working on a system that would take small "rooms" randomly (making sure they have all the important features!), and connect them randomly to make a complete, workable station, with atmos + networking +power.
"small" can be any size, even up to a full map.
When it loads a map module, it replaces all of the turfs in the XxYxZ box, but simply adds items to what might already be there.
As for how random it can be, that depends on the mappers. The simple example(and one I have got working) is sometimes replacing a random bedroom with a murder scene. A creative mapper could do something a hundred times better.
As it is right now, you can use it to pick a random version of a room(maybe have 3 chapel themes, pick one randomly at game-start?), shuffle preselected rooms(what bathroom is the executives' today?), or a combination where it first picks a room for each marker and then shuffles them(murder bedroom: one room in the bedroom group has a 1 in N chance of being a murder scene, and the locations are shuffled afterwards)
Currently, there is no system for automatically connecting new pipes mid-game, so at the moment, if a command to load a map were implemented, it would have problems with pipes but otherwise work.
Also, just because it is probably a good thing, I am putting a tiny bit of effort into making a very minimal code-wise version, with only object definitions so it would be worthless for anything but mapping or testing new icons from the map editor, but can't do anything in-game.