I wasn't able to get the PandaBoard to upgrade to Ubuntu Natty through a distribution upgrade -- the second time it completed the upgrade after about 16 hours and then hung on reboot -- but someone on #pandaboard helpfully pointed me to the Natty alpha images (note to self, I should have noted where they were). So I'm running Natty on it and, a small temporary dependency bug in our zope.html package notwithstanding, was able to
apt-get install schooltool from the Natty Universe repositories. So "Yay!" for that victory.
Poor performance running off the SD card is a known issue (yes, you might not want to run a server off the storage medium primarily used for photos in cameras), so I'm upping my investment a bit by ordering a solid state USB external hard drive for $70 bucks. So I'll have to expand my final case design a bit, and the cost is now around $300. On the other hand, it is a lot more plausible for real-world use with laptop-grade mass storage.
Also, with the current setup it is drawing between 3-5 watts. Pretty cool!