I've written a blog post at http://electron-swamp.blogspot.com describing a little about what I'd like to do. I also lay out a possible hardware lab layout that uses inexpensive parts to create an environment in which students can play and cause damage if needed but which can be restored to it's initial state.
There is a significant difference in what I envision from what I expect most other labs look like. The System Administration lab will not have any displays attached. It will not use the GPIO to control robotic or sensor hardware (at least at first). It will be self-contained and accessible only over a network. It will provide control access only using CLI based means (SSH and shells). There will be graphical feedback for the student activities using network and service maps and traffic graphing. The students will be able to add services which do respond in other ways: web services, time and name services etc. The students will also have remote power control for their Pi units and control of the first hop router.
This models well the kind of environment in which most system administration tasks occur.
The teaching model I envision is one I've learned from Allen Downey http://allendowney.com in his "Think *" books, especially "Think Python" http://www.greenteapress.com/thinkpython/thinkpython.html. Downey combines short chapters and lectures with guided (and free!) experimentation.
At this point I just have the functional map and parts manifest and some thoughts on design of the environment.

My estimate is that the Pi units and extra hardware for the students will cost about 85$US. The students will keep these at the end of the course and I hope that this price is not too high for the student "dues".
The lab "Pods" I estimate will cost approximately $325US to serve 4 students. A second layer of infrastructure to provide security and control resources for a set of pods I expect to cost $275US. So the initial outlay for 4 students would be $600US for reusable components and $340US "consumable" which the students will take home. This is well within the scale of cost for a typical Lego Mindstorms lab for the same number of students.
What do people think?
Does this look interesting to anyone?
I could use help designing an enclosure for the "pods" and beginning on the courseware itself.

