Perhaps Greg or someone in the know might enlighten us as to how they're approaching the truly awful AI...
I'm not a hardcore modder, but I was tinkering and thinkering last night about how to fix it, and I have to say -- I'm concerned.
Let's face it - the AI in I through IV was never all that bright anyway... BUT - you could paper over a lot of its faults by simply giving it huge bonuses or cheaper units. You could counter player exploits by adding unit attributes and changing AI build priorities. It wasn't perfect - but it worked, to some extent - because you could just always make the AI's lumbering stack larger, less costly, and more effective. The end result is that you never really "fixed" the AI (and yes, I'm of the opinion that without "true" AI -- and who wants to risk dealing with cylons genociding our grandkids -- you'll never make an AI algorithm as effective as a human player) - but since military play was only one aspect of Civ, you really just needed to make it tough enough to give the human player something worry about.
V, though, requires a completely and radically different approach. You're NEVER going to be able to solve it by reducing unit costs or giving the AI ungodly advantages with size. It's not even a matter of countering or balancing specific units.
In a hex/1UpT game -- the AI has to be able to analyze each battle or at least each campaign situation independently. It has to know how to position fast attack, melee, ranged, and siege units appropriately, then also shift that deployment as the field changes. It needs to know that sometimes NO moves is the best move. It needs to recognize that there are occasions where sacrificing X to save Y is the right move.
In short - it really does have to become a truly tactical AI... and Civilization has NEVER had anything close to that. It's never NEEDED anything close to that.
As much as I still like (or want to like) hex/1UpT - I worry that there is literally so much that needs to be done and what needs to be done is so radical, that for one thing -- other aspects (and I think there are other aspects that are a mess) will suffer.... Civilization was never supposed to be a military strategy game - I'd hate for it to become that - but it seems there is no other choice.