Personally, I would love if they introduced a taste of the Medieval to TS4, including a separate world that fits the criteria (older styled houses, dirt/cobblestone paths instead of roads, etc) so tha...
I've posted this suggestion so many times, I think it would work better as a gamepack myself and probably as a theme park or fair to fit into the larger game. But I don't think its high up on the development teams list, although with all the monsters we have I wish it was.