Swap SSD between two 2011 MacBook Pro 2011 machines I installed OS X on a 128gb SSD in a 2.3Ghz Core i7 MacBook Pro (2011) and I want to move the SSD instead to a 2.2Ghz Core i7 MacBook Pro (2011), all of the hardware is pretty much the same other than the different CPU.

Will this work WITHOUT re-installing OS X on the destination machine ?
Yes, it will definitely work. OSX comes with all the stuff you need to run on almost any Mac hardware (because they control it). In this case, the situation is better, because both machines are very similar.

You can safely switch them.