I used to play those on SC1 and Warcraft III when I was a kid. I haven't see any RP map in SC2 since beta.
edit : for those who don't know, it was a simple sandbox-like map with commands to use where you could build whatever you wanted on a preset terrain.
How the game unfold ? A player make a town with quests, another player create a hero and play the other's one area like a DnD game. Or every player make a town and they use diplomacy or events to interact with other towns "our town has been attacked, we require your help" etc.
You know it really is bad starting up old forums but i know this may sound a big weird but it would be a cool idea black and white infused with roleplayism i too myself like Rp... but yet none of sc2 maps have it anyone interested on actually making a game that would satisfy this forums wanting
oh and there are games you are looking for its just there popularity is less then none. there is only one i can think of... really sad to say that :( harvest earth next generation is the game you might be looking for sure its farming but its something on the road to betterness
yah i would though have a desire to make like a simcity or B&W2 Map just to make game because i too want to make a game where the object is not to kill someone but to go through time without hurting something :P if only people could make games like that