My Macbook Pro is 3.5 years old and still works pretty well, apart from the disk being full, frequently spontaneous wake-ups in my backpack which heat everything up alarmingly, and flaky wireless connection. Plus the turn of Moore's Law means I can now get a quad-core laptop and a lot more RAM and disk. So it's finally time to upgrade. I'm opting for non-Apple hardware; Apple have gone beyond the pale pursuing patent warfare and platform lockdown, and I can no longer live with buying their products. A Lenovo W510 is probably in my future.
Now I'm faced with a somewhat difficult decision: Linux vs Windows. There are good reasons on both sides. The best thing about developing in Windows is that it's good to have developers on the platform that most of our users use. VMWare record and replay is also very attractive. The Mozilla build and tools situation on Windows used to be terrible --- very slow builds, horrible profiling --- but it's gotten a lot better thanks to pymake and xperf. But Microsoft, while not as dangerous as Apple at the moment, still aspires to be, and I won't embrace them gladly.
Linux, of course, has the virtue of freedom, and a chance to regain Miguel's love. On Linux you get valgrind. But not many of our users use Linux, and VMWare's record and replay doesn't really work there. I'd have to use X11, which I loathe with passion.
Tough call. Another thing to consider is that whichever way I go, I'll end up using the other in a VM quite often. Dual-booting is also an option.