When I look at Apple's UI design, a lot of it seems to be about interacting with the device and not interacting with my task. Partly this is due, I think, to the amount and types of integration of apps into the environment (via Cocoa.) And partly, it's the fact that Apple's UIs/APIs aren't as generalized and engineered as Microsoft's -- which is to say, as an end user, you can do what you need to do, but there's generally fewer ways to do it and when you do it's much more defined.
When I look at Apple's UI design, a lot of it seems to be about interacting with the device and not interacting with my task. Partly this is due, I think, to the amount and types of integration of apps into the environment (via Cocoa.) And partly, it's the fact that Apple's UIs/APIs aren't as generalized and engineered as Microsoft's -- which is to say, as an end user, you can do what you need to do, but there's generally fewer ways to do it and when you do it's much more defined.