I'm pretty happy with the state of the game as it is, however I guess there could be work to integrate some more customization features, particularly to increase performance for some.
I suppose part of this depends on people's opinions of the national monuments pack, unfortunately I can't get much of an accurate opinion on them since they had due to the madness with reviews last summer.
Personally I don't see much of a graphical update plausible due to the cost + most people play with map modes that don't really focus on the beauty of the map.