So here is something really cool I just discovered. I decided to install the Mac version of Steam, so I could look at some downloadable games. When I got it installed, I logged-in with the Steam account I made nearly 6 years ago when I first bought Half-Life 2 for my PC. When I logged-in, I found out that the Mac version was available for me to download...for free! Now that is cool. The honored my license, even after I moved to a new OS. Valve rules!