ehm no offence, it might be my ignorance, but the map file is the .map file right?
I think this is a great feature and I'm very happy for what this will enable in dominions 3K. Space provinces as you suggested primarily. I have no idea how that thingie with the colors of the ground works but I'm sure it will fit different planets having different colors in addition to getting spaceprovince fights 

 . (take note Rdonj since I specifically gave the planets on your map different colors 

)
				__________________
				Want a blend of 
fantasy and 
sci-fi? Try the total conversion 
 Dominions 3000  mod  with a new and fully modded solar system map.
Dragons wanted? Try the 
Dragons, Magic Incarnate nation.
New and different undead nation? Try 
Souls of Shiar. Including new powerfull holy magic.
In for a whole new sort of game? Then try my scenario map 
 Gang Wars.