The problem with skins for your OS is not that they are used, but that they are used by people who don’t know any better.
I remember the scary days of Windows 98 where just about everyone customized the UI, and in far too many cases, to a point where the system was unusable by anyone other than the owner of the computer! It’s was a nightmare diagnosing a system like that, and next to impossible to have a productive tech-support phone call trying to explain how to get to Network Neighborhood by explaining which icon to look for after the f* user changed it to a bumble bee or some other totally unrelated rubbish.
An then with Windows XP, I’ve had cases where people have purchased a computer with Vista Pre-loaded, and when they came to me for tech support or for the installation of some software or drivers, it was discovered that the company they bought it from unscrupulously loaded some rubbish like Windows Blinds (for example) and fooled the unsuspecting novice that they bought a PC with Vista on it!
And what about software? WinAmp is a classic example of open skinning gone awry. At a guess, I’d say that at least 90% or so of the skins for almost any version of WinAmp are so damned dodgy, that the program is totally unusable. The same can be said for earlier version of Windows Media Player!
Whatever happened to the unified interface, where the common elements of any application, including OS utilities, where just that?
Personally, I’m glad that Microsoft has removed the skinability of Windows, and by allowing customization that can be done to such cosmetic items as desktop background and titlebar/border color.
Skinning is for people who have nothing better to do on their computers other than fool around without doing anything productive.