Wine isn't a part of the Mac OS. It's a (usually linux) binary layer that allows windows exe's to run in a unix-like system, redirecting system calls appropriately. Since Mac is Unix-based, you could get gcc and the rest of the compiling stuff linux people are familiar with, and compile WineHQ - Run Windows applications on Linux, BSD, Solaris and Mac OS X for Mac. Shouldn't take more than 10-15min to edit the autoconf file and configure-make-install, and you're done. Damn, I gotta stop the technobabble.

Or, you could dualboot windows, you could run windows in a sandboxed vm, remote desktop another pc running windows, or you could always get it for Mac you-know where.

So much for "Just works."