I don't think terrain self-shadowing has been implemented in the Georgia map - what you're seeing is higher contrast shading, which still looks great.
Look at the hills in the middle of your screenshot. On the top, the left half of the hills is shadowed. The same part in the bottom picture doesn't have any shadowing at all, so it shouldn't be just more contrast.
Besides, shaders and shadowing is one of the features that shouldn't need a new map to implement. Disregard.
