AI is generally about the last thing done on a game like this. We keep iterating gameplay until it's fun, which keeps screwing over the AI. Once the gameplay settles down (as it's doing now), then the AI picks up and gets a lot better.
Bruce is our slightly-above average control rod this time around for AI yardsticking. The goal, as always, is to have an AI that is fun above all else. We are spending more time this time focusing on the mid-level player fun factor, but we also have more AI folks on the project to account for that.
In terms of "fun" for the hardcore guys, we know this means kicking their ass but in a fair game. We've always had an AI that doesn't cheat (unless you're on the insane mode where it gets a resource boost). Our goal is to get a game where, even up, the AI can take our play balance group 1v1. I'm not sure we'll get there, but that's our goal.
dave