Isn't the real Starcraft 2 startup challenge spending launch day intensely focused on how to beat all of your competing startups, who are spending the day playing Starcraft 2? ;)
Some friends and I have the following Starcraft 2 challenge: We're all going to purchase it, install it and immediately play a game against one another without reading instructions, playing tutorials, or whatever. The first one to figure out how to play the game, wins.
Okay, from the website hits there seems to be alot of interest. I'm going to draft up a little website and organize a little tournament. Will post when the site is up.