After reading those creepy stories about Commodore and un-released Amigas (A3000p, A1000p, A300...) I made a trip into that historic repository that is
The Dave Haynie Files.
I downloaded the whole 10MB archive and there is a very interesting paper in the /devcon93 folder with some ideas in it about improving the User interface.
There are some already implemented things in hacks and third-party gui toolkits. Major stuff is about enhancing the looks, and there are a lot of details never done before on an Amiga, perhaps on any system. (Menus that transform in windows with controls on it??).
Visions of future from the past... A future that never happened.