My main concern is about this hype with every developer switching to OS X as their main platform. The issue here is that OS X is not precisely developer oriented. It is a pretty/colorful/stylish/whatever system designed to be easy to use.
The problem lies in the loss of control and productivity for the developer. It is a system design for non-experts used by too many software professionals.
Loss of control because OS X is a system without package management! Because many software doesn't compile cleanly on OS X and you need to apply ugly patches on top of it. Because many open source programs and tools shipped by Apple are outdated and buggy and this company doesn't care. Because it is not a simple OS where everything is under the control of the user.
Open source modern UNIX derivatives are not so simple anymore but from time to time some new project simplifies some aspect of the administration tasks in a reliable way. There are also bugs in open source platforms but at least you receive the fixes much earlier and you use unpatched software that probably is much more reliable.
Loss of productivity because its window manager is more than horrible. It is only OK for the sporadic use. The window manager is design to be so simple that it is useless. Switching between windows and maximizing them is ridiculously badly done.
I could say that Apple computers are optimally design to be just sold in the store. They just look better than the rest but that doesn't implies that it is one of them what you need to buy and use.
This can be reasonably explained with the rise of web development, where each day is more uncommon to use native languages and most of the developers are working using some kind of VM or interpreter. Which is perfectly fine except for the fact that these language's creators must hide in the core of these language implementations all this "portability crap" in order to keep happy their language users on OS X.
Many people would say that my window manager, my editor and all the time I spend on the terminal is too primitive for the age we are living. But the truth is that this is what most of the developers actually do. We edit and read tons of text, we control many machines remotely through the shell and we perform many automated actions driven by scripts. So, yes. I want a system that allows me to work comfortably with many windows, read and edit tons of text files and I want a powerful shell so that I can automate everything I am capable of.
Computing got fucked the day that the mouse was invented. At that moment system automation stepped back one decade. I don't like to be all day long typing, but at least I can automate many repetitive tasks.
What bothers me the most is the fact that OS X is a crappy UNIX when most developers nowadays work in an UNIX dominated environment where most servers run Linux with the software written by these developers.
So, no thanks, I don't enjoy these slow, broken, beautiful computers.