I decided to run my battery down to do the calibration as suggested in the MBP manual. I got one warning about imminent sleep, and dismissed it. As I was copying a folder, the Mac went into forced sleep right in the middle of playing the "copy complete" sound. It repeated this sound a half-dozen times before the system finally went to sleep.
It darkened the screen, the little white LED came up dully (as it does when the screen's asleep), and then eventually it went into full sleep mode.
I tapped the shift key, to make sure it was really asleep. On my PowerPC AlPB, this is ignored. On this machine, it woke right up. I used it for a few more minutes, and then it completely shut down losing anything I had not yet saved. This was pretty bad.
I've now launched XBattery and plugged it in. Let's see if it gives us any more juice. Currently: 5419 mAh capacity, 3 cycles.