To be honest, Macintosh and Windows both stole the "clever desktop analogy" from X. Apple made the windowed desktop usable (as opposed to the CDE *shudder*). Microsoft made it cheap.
All my Mac friends act like someone shot their dog and stole their wife. Cheer up, folks. Look at it this way: Between Linux on x86 and IA64 and Intel Macs, maybe we've got enough voice to convince Intel that Bill Gates and his 640K don't constitute the entire computing universe. Welcome aboard.
I wouldn't say that - both X and the Mac came out in 1984, and the first version of Windows was only a year later. Pretty much everyone "stole" it from Xerox around the same time ;)