What takes longer to install? What files aren't compatible with Windows?
Mac OS X is usually preinstalled with computers, I have no experience with installing it. Ubuntu and Fedora both install significantly faster then Windows XP or Vista, that include a lot of software in the install. Ubuntu in fact, can be completely installed while using Windows.
What formats aren't compatible with Windows? I can't think of even one. Maybe you mean the other way around, but that is not so true, except for maybe some really complex Office documents, and you can still open it and view most of the content. Even DRM'ed media is easily cracked, and any Windows Media format is playable with VLC at this time. Which of course, is multiplatform and runs on OS X and Linux, as well as Windows.
Anyways I don't think Microsoft will be able to maintain their monopoly. They aren't "DOOOOOOMed", but I see them becoming somewhat like a GE in a next decade or so.
I don't understand your last statement here? You do realize that GE is number 6 on the Fortune 500 list with 168+ billion in revenue and 20+ billion in profits. It is also the worlds #1 most admired company. You make it sound like a bad thing. Anyway, MS has a long way to go before it reaches GE status.