Forget all that stuff, here are the real problems.
In K-12 the problems are five.
1) Mandates. Schools get much of their hardware tied to grants which mandate what they are to be used for. My district was stuck in a state mandated Netware setup long after it was dead everywhere else, just for example. Combine with the natural desire to avoid having multiple incompatible platforms and the urge to make everything Windows is currently insurmountable.
2) Existing software. Find a school system that doesn't a decade of accumulated ties to Windows software. Grade management on the teacher's desk, Accellerated Reader, SAT Prep, kids eduware, etc. Almost none of which will run 100% in Wine.
3) Fear. All of the school system's IT people are Windows people and fear being unable to learn something else. They will undermine any effort to replace Windows.
4) Cost isn't an advantage. As the article implied but didn't come right out and say, schools DO NOT CARE ABOUT THE COST OF SOFTWARE. They usually get it in ways that aren't on their direct budget and commodity items like operating systems and MS Office are deeply discounted anyway. The vertical market stuff they do actually budget for will cost at least as much if available on Linux as for Windows and perhaps more and with less selection.
5) Office. In schools today they teach how to use a browser (usually IE) and Microsoft Office and call that teaching em how to use a computer. As soon as the little buggers can move a mouse they have 'em building PowerPoints. Schools are convinced they must do this "Because that is what they will need to get a job." We know learning Office 2010 now won't mean much in a dozen years when they graduate. We know that moving between OO.o and Office isn't that traumatic. They don't believe it and until we develop arguments that work this one is fatal.
And for higher education most of the above applies in general lab settings but for computer science education one more must be added:
There are no good texts on programming for the Free Desktop. Plenty of stuff on setting up a LAMP server. Plenty of information to write a CLI app in a dozen languages. But find a book with intro material on programming a GNOME, KDE or any GUI app for the Linux desktop. Doesn't exist. So you would be left teaching Java and Eclipse, which works as well on Windows and is easier to find support for.
Somebody wants to create a break through, write a good first year programming textbook using Python + GNOME. No figuring things out from looking at the C documentation for GTK/GNOME, everything they need in one book.