The biggest reasons seem to be stability and performance utilizing some features of OpenGL. It’s about time someone takes the big leap and wrangles the X monster. If you were to start from scratch right now, designing GNOME, KDE, XFCE, etc., all without Xorg’s quirks and limitations, would it come out the same? I don’t think so.

This is how-to-Install 3D desktop effects on a vanilla Fedora 10 installation (I tried this on a freshly installed Fedora 10, installed from DVD). Basically all you need to do is get 3d hardware acceleration enabled for your video card and then install the fusion-icon package and reboot. In the past this was easier said than done.