What do games tell us about intelligence?

Over the weekend Google DeepMind's alphaGo program defeated one of the world's leading professional Go players, Lee Sedol, in a best-of-five unhandicapped Go matchup. The final tally was 4–1 in favor of alphaGo, and a profound reality is upon us: a major stronghold of superior human intelligence has fallen. This defeat raises important questions for research on human intelligence. What can we learn from continued advances in gameplay artificial intelligence? What role can games play in measuring continued progress in research on intelligence more generally?