The 0.37 Better BTS AI is very cool no question.
I dunno about anyone else, but I'm starting to look through the code more and more, and there are still so many avenues to improve the AI even further. This game is NOT dead for many years yet, depending on what people want to achieve. For me, a better AI is still the holy grail.
The CIV4 SDK is an excellent platform to achieve this end. I'm not sure what the limits of the AI architecture are though.....However there is still an entire layer of structure that could be put on top of the current AI code, that would add so much more ability for the AI to organise it's activities and plans. Until that is done, the continuing story of the evolving CIV4 AI is not fully written and finished in my mind.
Cheers.