I love messy desktops. I can find anything if I have a search widget and all the current stuff on the top of the piles. The many variations of the GNU/Linux desktop are no problem at all until they become mutually exclusive, locking-in users. We are getting that way with Ubuntu, the most popular distro charging in some direction with its vision of the latest and greatest desktop environment while leaving users to make hard choices: to follow or to leave.
Jack Wallen at Tech Republic has a good article on this subject. see 10 ways the Linux community can fix the mess on the desktop. I don’t think it’s quite as bad as he writes. For instance, I would not agree that Unity should be killed. It is great to have yet another desktop environment. I do think Unity should not be exclusive. Many millions of loyal users of Ubuntu may not want to change desktop environments from GNOME. I think, eventually, Unity may achieve a level of functionality that makes it widely desirable but forcing users to change is undesirable. Users may have to reverse-engineer Ubuntu to put GNOME back or change distros. That is probably a waste of their time, not what IT should be about.
It is quite reasonable to ask all distros to make possible transitions of desktop as smooth as possible. In Debian GNU/Linux, for instance, there are many environments in the repository and all one has to do is choose to make one or the other the default at installation of the distro or any particular environment. The depth of dependencies of Unity make that quite difficult. Should one have to change video drivers to change a GUI, the high-level stuff? I don’t think so.
I am particularly worried about the future of X. X is so useful and flexible that it should not be sidelined. It is important that X runs on good, bad and ugly hardware, something unlikely to work with the latest and greatest video drivers coming down the pipe. A huge fraction of the world’s PCs are able to live on for years thanks to X and GNU/Linux. Change for the sake of the new, rich, commercially current hardware should not be an abuse of the less popular. A desktop ecosystem should not only be judged on how it treats the latest and greatest thing but on how it treats its aged/minority systems.