Yeah, it's a terrible pun, but you should have seen it coming.
Today marks the public debut of Valve's online gaming/distribution platform Steam on the Mac. OS X users can download the program here, but be aware that not all of the games available on the PC version of the service are available on the Mac version.
Actually, the number of games available for Mac gamers is extremely small at the moment (the two most notable titles are a free version of Portal and half-priced, massively addictive Diablo clone Torchlight), but Valve has vowed to release a selection of Mac titles on the service every week.
The company seemingly offers no advance word on what games they'll be bringing to Steam, but every week they fail to release Team Fortress 2 is one more week that they run the risk of my burning down their homes and killing their pets.