There's a very interesting academic study going on at the Simon Fraser University's Cognitive Science Lab in Canada, using Starcraft II rankings and replays to look at the attention, learning and cognition: http://skillcraft.ca/

The project's director is a keen gamer himself, and seems happy to do interviews and generally promote the project within the gaming community (he recently did an AMA on Reddit, http://goo.gl).

I think it's great to see games being used to do serious academic research into the way our brains work! The researchers are really in need of more low-level players to take part in their survey and submit replays, however. Go here to take part: http://skillcraft.ca/survey/. (Note that the researchers have said that it's really important to their research to both submit a replay and your Battle.net profile URL).