Looks like they are going to limit the APM of the AI. I wonder how they are going to decide the limit? I've never played StarCraft, but from what I understand very high APM is needed to play the game at the highest levels.
The top contestants were employing strategies that required APM an order of magnitude higher than what players could do. For example, in brood war, SCVs can repair any Terran building or vehicle but it is not worth the effort to repair goliaths or tanks for a player.
However, the AI could easily manage repairing it's tanks which makes the Terran army much more cost effective.
In SCII there is auto repair and other improved UX that probably limit the ability of novel strategies like repairing vehicles.
(it's also possible the system is receiving information directly from the game engine, but it's definitely possible to figure this out from nothing but the information on screen)
What would be really interesting is putting a similar smart AI on the tanks, which could make decisions like shooting at the highest concentration of zerglings instead of the closest one, or holding its fire if one lone zergling is in range, but a clump of them is about to enter range.
Human players already do both optimizations with widow mines, which are a unit that takes several seconds to prepare its shot so it's feasible to retarget. It's not feasible for humans to do this with tanks though as they fire immediately and automatically.
You could even see counterevolution as two AI algorithms become better at predicting what the other will do.
An AI limited to even 200 decision-driven actions per minute would probably have a significant advantage over a "500APM" player.
The point is to build ai that compete with humans using human strategies. Not to cheese with borked game mechanic exploits.
People were making custom AIs for starcraft 2 since it was in beta. They can't beat any human worth their salt.
Unlimited APM makes AI much less interesting from the perspective of game theory.
Think of it like a robotic boxer, except instead of an android, they build two 30 foot long walls of spring-loaded boxing gloves that close in on the human boxer. Yes, the robot punches the guy a lot, so the problem seems "solved" but it isn't really.