PC World reports that last week's launch of Steam on the Mac has been a huge success for the platform

Valve says that more than 11 percent of all Steam purchases are for the Mac in a post on its Steam blog. Nothing more than a first week rush from curious Mac users, you say? Maybe, but things look pretty encouraging for the Mac market when you take a few facts into consideration.

For starters, the only Valve flagship game to be released so far has been Portal, which was released as a free download. It's unclear if the 1.5 million downloads of Portal are included in that 11 percent figure touted by Valve. Second, Valve still hasn't released its other marquee franchises for the Mac yet, including Team Fortress 2, Left 4 Dead 2, Half-Life 2, or Counterstrike: Source. So Valve hasn't thrown all of its chips into the pile yet.

  Valve: Mac Games Make up 11 Percent of Steam Purchases