Google's AI has won the first two matches against a 9th Dan Go player! Doesn't look like they'll need all five games to determine the winner.
http://www.theverge.com/2016/3/9/11184362/google-alphago-go-deepmind-result
http://www.theverge.com/2016/3/10/11191184/lee-sedol-alphago-go-deepmind-google-match-2-result