I have an idea for how an AI could easily be made more intelligent as a placeholder until its done properly:
The AI can cheat, but not by getting free resources and seeing the whole map.
I think that the AI should be allowed to make up for bad planning by trading in buildings, units, and spells and getting new ones out of the mix. This solves the whole Starcraft-like tech tree problem, where the AI has to plan for every possibility.
So lets imagine an AI decides to focus on capturing resources and expanding early on. Then it sees you massing an army and moving towards its cities. It can then trash some of its buildings and technology, replace it with what it would have gotten if it knew you were going to attack early. In order to prevent it from always knowing what you are doing, you can tie this behavior to a %, like it has a 25% chance of not cheating, a 50% chance of cheating enough that it will survive but with casualties, and a 25% chance of really having no chance of being caught off guard.
I think that this would make for more interesting and less predictable games, as the AI would be better able to react to your strategies and not suffer for poor ability to plan ahead.
The way this would work is that once you, the player, sees that the AI has a certain unit or building, that is locked into place. So the AI can only trade in stuff that has not been seen by the player, or stuff that wouldn't make a huge impact (like trading one spell for another of the same type and level). Obviously, this AI would get weaker the more you scout it, so you would be changing the outcome of the game by deciding how much stuff the AI can swap out in a crisis.
Anyways, would you prefer an AI that does this, or the current AI?