XFCE hasn't been ultralight in a few years now. It is no longer recommended for netbooks and other underpowered systems. I think it might be a decent replacement for GNOME for many disgruntled users.
Personally, I'd recommend at least considering replacing most of your Linux desktop needs with Emacs and the command line. As the years have gone by, I've done less and less of my work outside of Emacs, a terminal and a browser. Even supposedly UI-heavy things like simple image manipulation are done faster from the command line with an imagemagick one-liner than waiting for Gimp to launch, reaching for the mouse, and clicking through dialogues. Sure, that way of working isn't for everyone, but the sort of people who read Slashdot might want to give it a try.