Empires maps are mostly big and scary if you are alone, or have only a few players. Smaller, tighter maps are better for those times. So some kind of adjustment of map size is needed. Script checks for player ammount in server by endgame (CV death, etc) and selects appropriate map sizes for next map.
SIP suggested something awesome for district. Effectively making it much bigger, with more corridors opening up as the players increase. Or it might have been Blizzerd who suggested it. I don't remember. It was still a kickass idea.
http://forums.empiresmod.com/showthread.php?t=10290&highlight=district it was a collaborative brainstorm i would say