PaulS:
Sorry, by "Arduino 2" I mean the Arduino beta IDE.
How do you get 2 out of
Arduino 1.5.6-r2 BETA (with support for Arduino Yún and Arduino Due boards)
Apparently through the magic of MacOS automatic naming. I left Arduino 1.X installed, when I installed Arduino 1.5.6-r2 BETA the app was installed as "Arduino 2".