Well, it looks like it was just the power adapter after all, thankfully. The guys at MBS left the MacBook connected to a known good power supply overnight, and eventually it charged up. Plus, I got my new power supply via Airborne this morning--- and surprisingly enough, they actually rang the doorbell and handed it to my wife, instead of just throwing it at the door and running like they usually do. So, good news all around.
This post was published more than a few years ago (on 2006-03-13) and may contain inaccurate technical information, outmoded thoughts, or cringe takes. Proceed at your own risk.