Is Red Hat the Microsoft of Linux?
Apple tries to move developers to a proprietary windowing system, incompatible with open source applications. [...] More likely, however, they'll just be shooting themselves in the foot, until finally someone integrates X11 into OSX more smoothly than XDarwin.
This is uninformed and wrong. Apple tries to get as many developers for MacOS X as they possibly can because MacOS X is their platform.
X11 cannot be "integrated properly" into the OS X at all. In order to integrate, applications have to use the OS X GUI. Any application that uses a different GUI is not integrated. Maybe it runs, but it will look and feel different and awkward. Since X makes no constraints whatsoever on the look & feel of programes, except that it suggests they use windows, most X applications cannot be integrated with OS X at all, except programs such as LyX which have a GUI independence layer or Qt programs as soon as the proposed Qt for OS X arrives, and even these only to a limited extent.