It may be a form of good‐story bias to ask, “Will AIs be good or evil?” as if trying to pick a premise for a movie plot. The reply should be, “Exactly which AI design are you talking about?”
A common reply to that might be: "the one(s) we are most likely to get".
Just noticed that Less Wrong has apparently not yet linked to Bostrom & Yudkowsky's new paper for the forthcoming Cambridge Handbook of Artificial Intelligence, entitled "The Ethics of Artificial Intelligence." Enjoy.