I like the idea of Civs changing names... and I wish they'd bring back the "civil war" option from Civ 2. You know, where, if you took a civ's capital city, it could break apart into two empires. Have something similar (maybe not the fall of a capital city, but maybe a good chuck of it descending into unhappiness for a while) happen to certain civs, resulting in the creation of an American, Mexican, or whatever civ. Could code it so that it was more likely to happen if the colonies were separated by oceans, or if the makeup of their cities - commercial vs. religious vs. military, for example - was different from the core of the civ.