Are you planing stuffs like independent civ evolution, being those based on their resources and knowledge, on the world gen? Something like tribals, then small cities, then nations... While others don't evolve because they have no resources(Like Colombo going to America). Each one evolving their own language... Something like prehistory to middle ages.
I had something to say, but I feared I would publicly pinpoint a subject that would make the thread potentially explode, and we don't want that.
I would love to see ethics being tracked down and interacting with each other. For example, a civilisation worshipping dreams would consider extremely evil to wake someone up and make this a capital punishment, but at some point a road connects them with another civilisation who doesn't see it as a problem. Then they could enter wars or one civilisation could talk the other into using its system or at least not to be bothered with it.
I think there was a DFTalk about this subject, somewhere...
This raises the question of different lifestyles, architecturally and economically. Are variations of lifestyle inside a race, without regards to ethics, planned to go in, like an entire human civilisation being nomad, or building temporary cities that are destroyed every 2 years, or food/water/cattle being considered a common property and handled at the hamlet/village level instead of personnal level, or houses built in a circle instead of a square, or underground instead of aboveground ?Technological evolutions have been discussed countless times. We more or less settle for the fact that while it would be fun to watch inventions and technology spawn and spread and be stolen, we don't have in a common Fantasy world much to discover and thus we would probably be more annoyed by the absence of features than we would be pleased by discovering them.