I like the idea of shifting traits, kind of like in Galactic Civilizations. Exept the shifting doesn't have to be good vs evil. And they should be based on how you're playing the game. Say you're a peaceful builder and you've been building a ton of temples and cathedrals perhaps you could gain half priced religious buildings. Even though you may be an industrious/agricultural Civ. I think if something like that is implemented they should definately be accentuating the manner in which you are currently playing and not be something that you can count on that is entirely unrelated to the way you've currently playing your game.
For Example say you're a militaristic/scientific Civ and a shift occurs it shouldn't necessarily be automatically drawn from either the scientific or militaristic traits, but should be determined by you're current city infrastructure and by the events you've been a part of in diplomacy/trade exploration and the like and be based on what you've been focusing on. This would allow for a more intense focus on specific startegies which should benefit the long term plan, or be a useful bonus should you decide afterwards to change your long range plan parhaps you could experience a shift in each age.
For Example say you're a militaristic/scientific Civ and a shift occurs it shouldn't necessarily be automatically drawn from either the scientific or militaristic traits, but should be determined by you're current city infrastructure and by the events you've been a part of in diplomacy/trade exploration and the like and be based on what you've been focusing on. This would allow for a more intense focus on specific startegies which should benefit the long term plan, or be a useful bonus should you decide afterwards to change your long range plan parhaps you could experience a shift in each age.