>>2153540
>Iirc, the map rewrite will be mostly about the changes to the cave generation

I don't remember all the technical details, but one thing the map rewrite was supposed to change was how the underground is set up. Right now it's a very formulaic thing where there's always three cavern layers and these are generated for each map tile seperately, with no connection between them. The map rewrite is supposed to give us a single, coherent and free-flowing "Underdark" under the overworld. Where you can even embark on top of a cave people settlement or something like that.

It will give us a larger number of surface geological features too, from irl ones (canyons, mesas) to fantastical ones (flying islands).

Atleast in the past Toady has also talked about how the map rewrite will allow us to have multiple "cameras": You'll be able to open a pop up screen during fort mode that shows your army invading another side and you can comand them around.

So all in all pretty cool. Pic related for Toady's explanations from almost three years ago.