Myungwan Kim seemed to be quicker to reach the right conclusion - IIRC, by the time that the fighting in the lower right corner ended, he was pretty sure of AlphaGo winning, to the extent of guessing that a move that lost AlphaGo around 1.5 points down there was because AG would win anyway.
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.