The issue with something like StarCraft is that it's a real-time game and so you can get to superhuman levels of play just by being fast enough. I suspect that serious effort put into a GOFAI approach to StarCraft could produce an AI that can beat human players in general, not by making the AI smarter, but by making it just smart enough and leveraging its ridiculous micro advantage. For this reason, turn-based games are always a more meaningful testbed for intelligence.

On the other hand, Go has a problem in that it's a perfect-information game, which I suspect makes it easier for existing AI techniques to handle. StarCraft on the other hand has a fog-of-war where players must guess at (and remember) what other players are doing, and I suspect that games with limited information like that are a better test for real intelligence. The ideal game for testing intelligence would be a highly complex and nuanced turn-based game with a fog-of-war in place.