One of the things about traditional Flight sims, or other places that try to replicate the real world, is that there are really no databases complete enough to let you do such things automatically. It always comes down to painstaking modification by hand in the end, and no developer has the time or money to do that except in very limited areas.
I think that with Outerra, and the ease of placing objects, roads, paths and probably even waterways, eventually, it may finally come within reach that individuals can easily edit their own cities, towns and neighborhoods; alone or even better, cooperatively around the world. Imagine the possibilities.
If I were Google, I might even be keeping an eye out on Outerras progress. For a number of reasons.
In the meantime, I can barely wait to see OSM in Outerra.