If you are like me you don't like to create a special backup or export file for every application. You just backup the entire hard drive to an external hard drive. This does add a few steps towards recovery of your address book when you upgrade to a new computer.
To recover your address book, you will need to do the following.
Go into your external hard drive and locate these files
Copy these files to the equivalent location on your new Mac.
From your backup, copy this directory
to the equivalent location on your new mac.
You are done.
Hope this helps.