“Mac OS X gave us a host of interface enhancements, for better or for worse. Some are seemingly frivolous, such as the whiz-bang animations that dominate Aqua, and others haven proven truly useful, such as the Finder’s column view. Personally, I dig it all.” The article at O’ReillyNet discusses the main Aqua enhancements, animated window resizing and the drawers.
I admit to not reading the article, but I would like to say that Finder’s “column view” has been in WindowMaker for a while.
And even longer in NeXT so what’s your point?