The iBook is still unusable: it still refuses to boot into target disk mode, and thus is in a bit of a coma (to anthropomorphize the situation). It’s very sad, and very frustrating.
What I plan on doing is extricating the iBook’s internal hard drive and transplanting it into an external firewire enclosure that will allow me to mount it onto another Mac. This way, I can salvage the files that haven’t been backed up in recent moons (yes, fellow techies, I fell into the “do as I say, not as I do” camp with regard to backups of files – that’ll teach me).
Opening up the iBook will also give me a chance to look at the logic board and see what’s gone awry. My guess is that there’s a crack in it somewhere, just small enough to disrupt the circuits.