One little thing that looks quite bizarre. When you siege an enemy's city and start to bombard it so that the population decreases, the moods in that city begin to alter so that on the next turn you find out that your foes are celebrating a 'i love the president' day. Very silly of them.
I don't like the pattern, that was used in civII, when population moods depended on enemy presence near the city, but at least citizenship's moral should decrease when population number decreases (due to bombardment or starvation, but not after you create worker or settler). And may be it should increase after a city sucessfully withstands the siege and an enemy has to withdraw its troops.

Well, though I can't say for certain, I get a sense that sieges will be a LOT more brutal than in previous versions-if only because of the ability for sieges to cut a city off from any food it recieves in trade-this, in turn, will apparently lead to lost health and-therefore-a drop in population (even without you having to bombard them). Hopefully if health and happiness are closely connected, then perhaps happiness will take a dive too.
Also, remember that with specialisation of cities becoming more important in Civ4, losing population points is going to be disasterous for you!

Yours,
Aussie_Lurker.

Good point Aussie - the mechanism for the effects of a siege seems to be there. Cutting off the road trade network in Civ 3 only took away the luxuries which never had a massive effect. Its good food for thought pardon the stupid not-so-obvious-or- clever-pun.

hope you are right, aussie. but as you say it would work only IF happiness is connected to health.
i'm not speaking about damage. damage from population drop is obvious. i'm only keep being suprized that city gets damage and celebrates it. so in my opinion it would be right that a fact of each face lost in the city should invoke one more face becoming unhappy for several turns.