Judging by these forums, I think we'll see major changes to the espionage system coming soon. I've taken notice that there is virtually nobody on these boards coming out to defend the current espionage system as it is. It's a tedious system, and Firaxis will listen to the gamers. A big emphasis was put into "less micromanagement" for civ4, at least the "tedious" types of micromanagement... I, for one, am tired of looking at the AI's espionage points to see who just poisoned my water supply again.
Another thing -- my cities have been poisoned about 9000 times (marathon/emp/solvers patch) but I have never, ever, ever seen the Foment Unhappiness used against me. Whats up with that? All the AI seems to do to me with espionage is constantly poison my water... and honsetly id rather they did anything else because that is insanely annoying.