How Dangerous is Artificial Intelligence?

In Avengers: Age of Ultron, the villain (Ultron) starts out as an artificial intelligence experiment gone wrong. Is this just Hollywood storytelling, or should we be worried about a future dictated by robot overlords? To help answer this question, we've teamed up with the awesome Rusty Ward over at Science Friction! Check out Science Friction's episode on the science of The Avengers! Where do YOU think artificial intelligence will take us?