How big a deal is this? What, if anything, does it signal about when we get smarter than human AI?
This is a big deal, and it is another sign that AGI is near.
Intelligence boils down to inference. Go is an interesting case because good play for both humans and bots like AlphaGo requires two specialized types of inference operating over very different timescales:
DeepMind's go AI, called AlphaGo, has beaten the European champion with a score of 5-0. A match against top ranked human, Lee Se-dol, is scheduled for March.