That actually wouldn't be a bad idea. As someone pointed out, I also feel that filesystem hierarchy, window frames and the desktop metaphor is now outdated and overly stretched. Imho, they would be better come out with a whole new OS with no backwards compatibility, while keeping developing windows for the time necessary (10-15 years) to allow most of its users and software a 'transition' to the new system.

If they don't do it, someone else will do.