Pinched ETCLs OLPC and started hacking on it to see if I could update the OS.
Had to open up the wireless to get online, then ran a firmware updater (instructions and direct link to firmware images), followed by an OS upgrade (instructions and direct link to images).

RESULT: all is well. New firmware installed happily as did the new OS. WPA2/AES works (not sure about SSIDs that aren't being broadcast, though).

Of interest is the VMware images available from here.