Heh, player support, [sarc]why would they need to care about that[/sarc] when working on their art?
I assume that such a thing could be done in a few years. There is source code floating around the internet that would go a long way to implement this group of features, even if they were only used as study material.
So, it would be the ability to create buildings in PvP areas, and the ability to destroy them. The ability to hire NPCs, station them, and give them orders. The ability to place an inventory in a building or an NPC that the NPC understands how to access for trade. The creation and destruction of the buildings would probably be handled by the same server that controls the NPCs, so that as long as the village is destructible, the NPCs can defend it.