I am all for scriptable AIs, even though I am crap at designing them. I really hope and think it would be reasonable to expect that we get them by Dom4, but-ironically enough-you can make the AI in the game better, providing you're smarter than the AI
Lots of things can be done to improve it indirectly, through map editing and nation editing-it would be great if some experienced person would take it upon themselves to redo a set of the current nations specifically for use by the AI, and that future modders then followed suit with new nations, creating 1 mod for the basic MP nation and 1 for the AI SP version. I would also love-and again it's pretty reasonable-if Arena Deathmatches could be toggled on and off at the beginning of games, either whole cow or on a per nation basis.