The sexy OSX-running hardware can also be set up just fine, and quite comfortably, as a Windows device. The folks I see toting OSX machines are mostly using it as a shell for their Windows VM's.
Myself, I've got a 50/50 split between OSX and Linux. It works okay to switch between the systems, of course KISS principle applies ..
I know, one just needs to attend a Games Developer Conference to see Windows being used instead of Mac OS X.
Still, I am yet to work on a company that allows buying Apple hardware instead of Thinkpads to end up installing Windows on it.
Everyone else is on Windows with UNIX boxes available as servers.