I have run all but dry of understanding for programmers that willfully pick Linux as their platform of choice. I know a few that are still stuck in the rut for various reasons -- none of them desire.
I would have a hard time imagining the satori of someone who was still on Linux. If you don't care enough about your tools to get the best, your burden of proof just got a lot heavier.
So if you haven't switched already, stop procrastinating. Get it over with. If you have any desire working for the rising rank of companies building their business on open source technologies, you don't want to carry a liability like that around on you resume. Being labeled a 2008 Switcher is bad enough.
Apple will continue to trounce everyone else for the preferred expert platform. The stigma of using anything else than Textmate will increase. (Watch the screencasts)