Silly me, I needed to observe the controller itself, not the values...
duh! :-p
[[NSUserDefaultsController sharedUserDefaultsController]
addObserver:self
forKeyPath:[@"values." stringByAppendingString:preferenceKey]
options:NSKeyValueObservingOptionNew
context:NULL];
I have a preferences controller (PreferencesController) that controls
a preferences window. It would be quite nice if I could observe
changes to all of the preferences via key-value observing. In IB I
also have an NSUserDefaultsController that's hooked up to all the
controls, I've tried o