Well. KDE was an example. I think the gui could be more customizable (and not via external hacks). So, maybe even the standard aqua and brushed metal etc appleistic ways could do. BUT give the option to choose how much energy you put to your gui! Not everyone has the latest, nicest, fastest and biggest machine, and sometimes some tasks take too much resources.. in those cases it would _jut_ be so nice to have a few options to reduce temporarily the gui (like disable shadows and everything needing calculating, jsut for the time of running some programs).