I'm pretty sure the AI doesn't plan for victory conditions.
It seems the developers just built a general AI logic base, and that's it. My reasoning is:
a) It seems like all AI cities are set to "auto-govern". The AI masses settlers when losing a war...
b) It seems like all AI workers are set to "auto-work". Workers treat any given terrain the same, regardless of the AI civ involved...
c) Pretty much all AIs act the same. Mass settler then mass build "auto-build". Eventually one AI has a "diplomacy factor" and "aggression factor" that makes it fight a war for a few turns.
d) The research rate is very predictable (there's a calculator). The AI doesn't bee-line anything, even if losing a war, losing a culture battle, stuck on an island, etc... The exception to this is, sadly, the Nationalism -> Fascism -> Communism slingshot, which is the AI's way of saying "I want to avoid Infantry at all costs"...
e) The AI just doesn't "react" to many things. Probably because it was never programmed to. If it's 1000 BC and I march up to AI capitol with a SOD, they may still be annoyed with me... They just don't react outside of a few "per-turn number calculations"...
When I think about all the above, it seems like the developers just took the steps to "make the game", and didn't go much beyond that. Even 2 expansion packs to Civ3 didn't change the AI behavior much. Maybe improved the "auto" settings a little, but that's it. They were probably saving AI thoughts for Civ4.
I don't blame the developers though. Programming "better AI" just isn't as cost effective marketing as "programming pretty graphics"

But especially as the US economy goes down, I don't expect there to be many "better AI" games out there... Budgets are just too tight, and when developers present the game to their bosses (for paychecks), the graphics & playability are 95% of the requirements..
Dang, what I just said actually makes me sad

I guess the golden-age of great gaming is over...

!! Hello world of shallow mass-produced incomplete no-patch console games !!
Re: attitude issue
AFAIK AI attitude (pleased, annoyed) towards you is based on several things:
- Difficulty level affects base attitude
- Preferred Government / Shunned Government
- Culture Graph: The programmers wanted to make culture useful...
- Current Trades: Sign an alliance and *bing* instant Pleased mode
PS:
OMG I just saw a "Civilization Revolution" advertisement banner

Wonder if the AI will be "watered down" in that game too. Or maybe its designed for MP !!
Kill 2 birds with 1 stone !
EDIT: Removed false data from AI attitude area