I do not know much about linux but what about KDE
The amount of programming involved in porting KDE or Gnome to AOS would be signicant. First there would have to be some sort of X implementation, then you'd have to port the toolkits for KDE (QT) or Gnome (GTK) (whichever you wanted ported) and then you'd have to port the actual interface system. Not a trivial task. Besides, X is kind of slow. It's really quite good for what it is, but slow nonetheless. It was really designed for a multiuser system and the Amiga (at least through the 4.x versions) will not be multiuser, AFAIK.