Does Apple use bindings in any of their programs? One would think that if it really was such a great feature of Cocoa, that Apple themselves would utilize it, or maybe most of their apps were started before bindings existed in a mature form...
It's hard to say but it should be easy to find out by doing a classdump on some of their programs. You should be able to tell by looking at the instance variables. As you say, a lot of their programs predate bindings so unless they've refactored the code they won't use them.
That's interesting. Maybe they used Cocoa and Cocoa Bindings to be able to shove something out the door quickly to hamper the adoption of Aperture. One should think they'll move to their own Adam and Eve framework for user interfaces when they go cross platform.