There have been a couple of brief discussions of this in the Open Thread, but it seems likely to generate more so here's a place for it.
The original paper in Nature about AlphaGo.
Google Asia Pacific blog, where results will be posted. DeepMind's YouTube channel, where the games are being live-streamed.
Discussion on Hacker News after AlphaGo's win of the first game.
So what do you see as the mechanism that will prevent anyone from handing the AI those keys, given the tremendous economic pressure towards doing exactly that?
As we discussed in Responses to AGI Risk: