This is an interesting blog post asking the question “Would you use Windows if it was GPL?”
Personally, I would say no way! Although I do prefer to use open source software when there is an option, I don’t automatically shun anything that is closed source. I use Ubuntu not only because it is free software but because it is better. Linux is a better designed OS. And I have much more choice of things like my window manager, desktop enviroment, and software. Switching Windows to GLP would not fix its problems.