I can only assume that either Steam is needlessly holding back an American release or the delay is publisher enforced, either way it won't help sales. If StarCraft II were to debut in Korea two months ahead of a US release, what do you think would happen? Arbitrary time gates only exceed in promoting piracy and disenchants gamers by fostering an image of elitist snobbery. Also in the cards is the ability to dissuade game companies from using overseas publishing by appearing to be a criminally apathetic marketer or simply not localizing and publishing overseas at all.
Pirate Academics: Time Gates = Less Revenue
Steam has just released an update to Twin Sector, a new Portal-type Physx game published by Head Up Games that fixes some crash issues. I would be excited about this except that the game hasn't been released yet. In fact, it's two months away to release. Even better is that the website (though in German) states the release date as Sept 17, 2009. I can BitTorrent this game today, in English and complete. I could have done so a week ago, coinciding with the above release date and after playing the demo, I sure as hell want to.