It actually is pretty much all reusable widgets. Buttons in the corner of the screen? We can call them "navigation widgets". Buttons in the middle of the screen? We can call them "action button widgets". Buttons on menu items (like Delete)? We can call them "menu button widgets". They can be reused across your entire OS.
The issue is trying to pare your widgets down to their bare minimum. The minimum you can get away with depends very much on the context of the widget.
In iOS 6 they used the same design for navigation widgets as action button widgets. This made them consistent between the different widgets, but left the navigation widgets slightly heavier than strictly necessary.
In iOS 7 they pared each widget down to the minimum they could in the particular context the widget is used in.
The result is screens that individually look like they're made up of inconsistent widgets, but OS-wide the use of the widgets is consistent. Whether that's enough I guess we'll see as more of the general public use iOS 7.
The issue is trying to pare your widgets down to their bare minimum. The minimum you can get away with depends very much on the context of the widget.
In iOS 6 they used the same design for navigation widgets as action button widgets. This made them consistent between the different widgets, but left the navigation widgets slightly heavier than strictly necessary.
In iOS 7 they pared each widget down to the minimum they could in the particular context the widget is used in.
The result is screens that individually look like they're made up of inconsistent widgets, but OS-wide the use of the widgets is consistent. Whether that's enough I guess we'll see as more of the general public use iOS 7.