Minor WC prediction:
I've played an awful lot of raging barb games, and in my experience having that much open area in the WC game could lead to multiple entire civs eliminated by the barbs. Difficulty level doesn't seem to matter much when you have the sheer numbers of barb metal units and horse archers pouring in and the actual civs can't connect resources. Raging barbs are going to be THE defining feature in the upcoming game IMO. I haven't looked at the map more than a few seconds yet, but I'm going to strongly consider the wonder-building civs because of the GW. The AI on any level is just terrible at playing against raging barbs.