I just switched to Ubuntu again - on a two year old Macbook Pro 4,1 though.
To tell a bit about the software side on a Mac:
As long as you don't mess with the system, it runs nicely. Recently I wanted to have a look at clutter ("software library for creating (...) graphical user interfaces") which depends on newer versions of the libraries that ship with OS X. After fiddling around with building it myself (or building Formulae for Homebrew which is a simple and nice package manager for OS X) I decided to go with Ubuntu and Awesome as my window manager. There was just too many barriers in the way.
For web development, OS X was nice. Unfortunately I'm also toying around with a lot of music software which rarely has an OSS equivalent.
Some points on Apple hardware: The build quality is very nice. It might not have the latest stuff, but all components they ship are well integrated and usually don't get you into hassle (as long as you stick with OS X). I honestly don't want to miss the multitouch trackpad.
Conclusion: If you can live with the system that OS X is, go for it. Perhaps you'll get pissed some day about the missing freedom some day. Don't expect that the hardware in a MacBook will fully supported in a Linux distro
I honestly don't want to miss the multitouch trackpad
These are the key take aways, OSX is good for web / mobile development and the track pad is one hell of a plus for going with a MBP. I would not use OSX for C or C++ development or any system development for that matter, but for web and mobile it is a great system.
To tell a bit about the software side on a Mac: As long as you don't mess with the system, it runs nicely. Recently I wanted to have a look at clutter ("software library for creating (...) graphical user interfaces") which depends on newer versions of the libraries that ship with OS X. After fiddling around with building it myself (or building Formulae for Homebrew which is a simple and nice package manager for OS X) I decided to go with Ubuntu and Awesome as my window manager. There was just too many barriers in the way. For web development, OS X was nice. Unfortunately I'm also toying around with a lot of music software which rarely has an OSS equivalent.
Some points on Apple hardware: The build quality is very nice. It might not have the latest stuff, but all components they ship are well integrated and usually don't get you into hassle (as long as you stick with OS X). I honestly don't want to miss the multitouch trackpad.
Conclusion: If you can live with the system that OS X is, go for it. Perhaps you'll get pissed some day about the missing freedom some day. Don't expect that the hardware in a MacBook will fully supported in a Linux distro