What Features Would Make a "Better" GUI?

Rudyatek asks: "When it comes to desktop OSs, there has been much talk about 'the end of the desktop', 'reinventing the GUI', etc. Usability has become increasingly important as we battle the ugly UIs of Windows and X11, and watch companies like Red Hat and Ximian try to improve them. But I'm curious if anyone has any clear ideas on what a truly 'better' UI would really be like? As a hobby OS programmer I have a great interest in alternative OS ideas, and this is one that I hear more complaining about than actual ideas. Anyone have ideas?"