I haven't done production work on a Windows machine for a long, long time. My desktops have been Linux since 0.99pl11 (was that '93?). My laptops were Windows until Linux started working on them, and then I switched.
It was good. I put up with the hassles: the upgrades, the incompatibilities, the laptops that would talk to some video projectors but not others. I got behind in my patching, and had a server root-kitted once (well before we had an online store, in case you're concerned).
As the business grew, I found myself spending more and more time admining boxes. So, somewhat late, I made the switch maybe 3 or 4 years ago, first with an Apple laptop, then with a Mac Pro. As I grew more and more confident in the decision, I switched more and more of what I did to OSX. A bunch of our externally facing code runs on Linux and BSD, but it is all administered by third parties—folks whose job is to keep up with all the stuff that needs doing. Everything else runs on Macs.
And I've never really regretted the switch. I still don't.
But, like miners keeping an eye on the canary, I monitor the one real thing that makes my switching viable. The key benefit of switching for me is the lack of hassle. I spend a bit extra for stuff that just works. .Mac syncing lets me move from desktop to laptop without a thought, but now I have a syncing loop where each machine tries to override information that is identical in the other. Things just aren't as smooth as they were.
Am I regretting the switch? No. OSX works well for what I do, and it gives me access to tools I need (such as InDesign for covers, Sibelius for scoring, and so on). But I'm also not such a acolyte that I'll never move off the Mac if I start seeing the kind of hassle I used to experience with Linux reentering my life. Modern Linux distros have come a long way since I last used one on a laptop, and I know that I could probably switch if I needed to with little regret.
So, what do I want from Apple, both tomorrow at MacWorld and then over the coming months? Easy. I want to see fewer cool features—features which seem to add problems—and a refocusing on what made Apple the machine of choice for a certain kind of developers. I want my Mac to be as hassle free, secure, and reliable as it was when I first started using OSX.
Right now, the hassle-free canary seems to be somewhat distressed. I'm monitoring its health closely.