It would also be kinda cool if the disposition of civs - or of societies, ruling classes and individual rulers if they were going to break it down like that - changed over time, whether suddenly in response to events or more gradually.
In GalCiv II there are events that alters governments, diplomatic relations, and their moral code. Therefor i suspect that these will make their reentry into the game.
Examples of events that are in GalCiv 2:
Leader was assassinated -> There is now a state of war between the two races named in the event.
The government was overthrown ->The diplomatic relations between the two named races improve.