It's important to remember that a free (as in cost) license doesn't mean that implementation and support are free, but when an Open Source program is good enough to replace a program with a hefty licensing fee, I can see more and more education institutions making the change. And when you look at an example like the State of Parana, Brazil, where they have 12 people running 44,000 school computers (over 2,000 schools) because of Linux and Open Source Software, the possibilities for more ubiquitous computing become pretty darn compelling.
Just as interesting to me is the Open-Source-AS-education angle, as opposed to the Open-Source-IN-education examples. Teaching technical computer classes with Open Source software has a strong pedagogical basis, but even more than that, would have significant practical benefits to students--and yet, we rarely--if ever--do it. Somewhere in the range of 70% of the world's webservers run on the Open Source program Apache, and yet it's just not taught anywhere. Linux, Apache, MySQL, and PHP/Python/Pearl are serious business tools that can be obtained for free, have open code (great for learning), and will run on old computers. So why is it that we aren't teaching them to students who could actually use those skills to get a job out of high school? Maybe it has something to do with the lack of advertising dollars being spent to promote them to educators... :)