What is user-friendliness actually? The way I see it, it's about to what extent the software (be it an application or OS) actually lets the user get the work done, allowing the user to have a good work-flow. Without too many annoying pop-ups and attention-hijackers from the mandatory arsenal of built-in crapware you find in any PC with Windows pre-installed.
In this sense, Linux may be as user-friendly as OS X, but in its own terms for those who are familiar with it. I'm not necessarily referring to the command-line interface (though it usually provides far more informative feedback than any GUI can do), but e.g. the desktop-cube for those who run the K Desktop Environment (Linux has many GUIs).
User-friendliness is not to be confused with newbie-friendliness. Before I started using Windows in 1992/93, I was quite comfortable with the DOS interface and it felt awkward at first to move a pointer around on the screen, clicking the icons. However, Windows was newbie-friendly enough to get me into it within a day. But was it user-friendly? Did it help me get my work done? I feel it's working against me. Even Linux is better than Windows this way, and the way I see it, the steep learning curve of Linux is outweighed by its user-friendliness.
So - Steven Paul Job - I recommend you try out Linux first (either Ubuntu, Mint or Mandriva), and then by using only Linux for 2-4 weeks. After un-learning all your Windows-habits, OSX will work like a dream for you.