While Meer's been battering his way through it, I haven't had a chance to actually play the new Beyond the Sword pack yet (Though the hype around it has caused me to have a vanilla-Civ4 relapse). However, it looks like I'm never actually going to get a chance to play it as the developers intended, as - by all accounts - I should immediately patch it with the latest Unofficial patch from Solver over at Apolyton.
Where this becomes officially unofficial is that the patch includes a load of fixes that Blake - responsible for the improved AI in Beyond the Sword, among other things - has developed. There's a long list of general improvements, but let's go for some of the Blake specific ones.
* Fixed AI airstrike bug
* AI now only capitulates to the team which has done them a majority of the damage.
* On non-aggressive AI, the AI's are more aggressive early in the game.
* AI trains more units early in the game.
* AI SHOULD do a better job of bribing other AI's (this may or may not work)
* The cost to Bribe AI's into war now uses a new algorithm, it better reflects the impact of the bribe (ie a large AI charges a lot more to be ordered around). Generally bribing will be more expensive, especially cases where it used to be excessively cheap.
* AI's tell you to sod off if you try to bribe them onto a victim with an intact nuclear arsenal.
* AI brags about it's nukes more.
That Blake has managed to make the game act like I do when I play Defcon is proof that the Turin test is about to be completed. Our robot overlords live among us.
As a quick aside, I find this sort of blurring the lines of the official/unofficial releases for games fascinating. See also the guy who made the improved Shaders for STALKER which just made the game much better... which was then worked into the next patch.