This is probably going to sound a bit far-fetched, but here goes…
What If it were possible to create an application that allowed the GUI to be completely customised? By this, I mean a bit like Icon-O-Matic did for the Haiku icons, hence the title. For example, objects like window elements, scroll bars, shortcuts, etc. could be recoloured and altered slightly, or even replaced with other vector or bitmap images either from files, or vectors drawn inside the program. The entire desktop could be changed to feature a menu-style interface, or be command-line based. Possibly, the user could type scripts to change how objects behave, and what they do. If it wouldn’t take too many resources, maybe even videos could be included as splash screen elements, backgrounds, or start-up thingies.
Anyhow, I just thought I’d mention this as a possible concept, although I’m probably just talking rubbish.
T’raa for now.