While the Mac is a far superior platform, there are still one or two significant drawback compared to PC's: one of them is Microsoft's Windows Media Player for the Mac. A new bit of software has been released for the Mac that puts the full WMV codec right into your Quicktime player, and also into the Quicktime plug-in for your Safari or other Mac browser. So when you click on Doug's awesome videos, they will play right in your browser. Not only will they play, they won't hang, you can pause them, you can rewind, etc. Microsofts WMP couldn't handle any of these.
You'll probably be fine with the WMV Player version. It's only $10. If you want to be able to import WMV files into iMovie or Final Cut, get the Pro version of the Player. Get them here:
http://www.flip4mac.com/buy.htm