I have an intellectual issue with using "probably" before an event that has never happened before, in the history of the universe (so far as I can tell).

And - if I am given the choice between slow, steady improvement in the lot of humanity (which seems to be the status quo), and a dice throw that results in either paradise, or extinction - I'll stick with slow steady, thanks, unless the odds were overwhelmingly positive. And - I suspect they are, but in the opposite direction, because there are far more ways to screw up than to succeed, and once the AI is out - you no longer have a chance to change it much. I'd prefer to wait it out, slowly refining things, until paradise is assured.

Hmm. That actually brings a thought to mind. If an unfriendly AI was far more likely than a friendly one (as I have just been suggesting) - why aren't we made of computronium? I can think of a few reasons, with no real way to decide. The scary one is "maybe we are, and this evolution thing is the unfriendly part..."