Mockups for KDE 4 and GNOME 3 (scroll down to the pictures) - looking fairly alike? Which is no bad thing. ;)
Well, I can't say it enough times: there are clear relationships between different data types, especially multimedia, and these need to be taken into account in interface design. An example of this is my Mugar project (interface description at the bottom of page).
What I mean is, slideshows want music, phone calls want to go into the address book, photos may want to have character recognition performed on them, text messages may want to be forwarded as emails, spreadsheets may want to be converted to databases, and address book entries may want to be emailed to colleagues.
So you'd identify the sensible interactions of your datatypes, and implement these in the interface. It looks like GNOME and KDE are beginning to learn this. Also, if anyone can tell me what this strategy is called, do please let me know!
Like I've probably said before, this is what I think Apple are up to with their Automator. Once they've found out what users are actually doing, they'll concentrate on those workflows in their GUI design.
Technorati tags: GNOME, KDE, gui, Linux, Desktop, Usability