The One Laptop Per Child program is creating a $100 laptop suitable for use by young people in developing countries. It has enough weight behind it that it's pretty much guaranteed to produce something (though we can argue about whether laptops are more important than immunization, and whether they'll go to the really poor, or to the burgeoning middle classes).
Ivan Krstić's keynote at PyCon 2007 was by most accounts the hit of the show. The OLPC will run a modified version of Linux with an unconventional user interface. There aren't "files" per se, just suspended activities; sharing is ubiquitous; the user is in control of multitasking; and the security infrastructure (BitFrost) has quite a few new wrinkles. It's all open source --- you can download and build it right now on a variety of platforms. There are lots of opportunities in this for course projects in UI design, networking & security, operating systems, and other areas.
I'm particularly interested in figuring out what kind of software development environment could be built to run on the OLPC --- there's a "view source" button built right into the system, to encourage users to explore, and the prospect of hundreds of thousands of bright kids from dozens of cultures figuring out programming on their own is pretty exciting. Eclipse and other heavyweight tools are definitely not the answer, but I'm not sure what is...
Later: here's a YouTube video of the interface in action. Thanks to Jonathan Lung for the link.