Adding on to the previous posts, this is potentially indicative of a huge shift at Apple. Before the iPod Touch they didn't give games the light of day. They didn't care. Within the last year they're suddenly show casing games in their ads. (Yes, they did show of Halo back in the day but look what happened there...not that it was directly related to Apple being less than helpful with game companies.) If Valve suddenly changed their mind with respect to mac games because of support from Apple it could have farther reaching implications than just Steam.