Standard user interfaces approaches would be supported using a library of templates, built on top of the structure above, designed to be common for all platforms, but easy to specialise for efficient access to a particular platform.
In the case of Wimps (not the usual Weakly Interacting Massive Particles, or fat nerds, but Windows, Icons, Mice / Menus, Programs), a lot of work has already been done in determining a generic set of features required, and this work should probably be filched. In terms of other interfaces, such as mobile phones, I suspect a common template structure can be used but this may need work to identify an appropriate design.
In the ideal world, the GUI template model would make poor user interface design difficult. However, this would mean the consumer electronics industry would be unable to use such a library.