ITWorld has an interesting article comparing Windows 7 to OSX that’s worth a read.  While it is definitely a one sided comparison (the way its written at least), it compares 10 different UI points.  I can’t say that I disagree with the conclusions or the UI points chosen for comparison. The items compared include:

• Startup
• File Window
• The Taskbar
• Gadgets
• Control Panels
• etc.

If you haven’t tried Windows 7 yet, and are curious about how it compares to OSX, then this will give you a decent idea of how things line up.