A new stable release of CakePHP has just been released a few days ago, version 2.3.  With this many great new changes have come out of it.  You can read the full change log here:

One of the things that immediately caught my mind was this great big bolded sentence:
IMPORTANT: Model::find('first') will now return an empty array when no records are found. Make sure you update your tests!

Immediately after reading this I thought major code changes were going to be required; however, luckily my fear was unfounded.  Let me provide an example...