Bugs and balance should certainly be top priority, and balance may even help AI.
However...although I do play single player, including an AI in a MP game wouldn't be very fun. AI's and human players should not be mixed...it becomes a game of abusing the AI to get advantage.
No game as complex as dominions is going to have an AI with no weaknesses, and putting one in MP is just asking people to beat it up for its riches.
And if PBEM takes too long for you try a networked game. Mine's past turn 20 and it got set up Last week.
