How to make adobe cs 6 open my rw2 files by default

The other way is if you use bridge.  Bridge-Preferences-left hand side of window select-file type associations then you can select which app should open rw2 files.

I usually have to change that when I teach PSE as I use bridge but show organizer and go through several items. When we get into PSE I am usually navigating through bridge.

Ciao,

Lou Cioccio