Nice. I've been reading the AVRlib docs, and it should have occurred to me to write a reflexive sketch and listen on the serial port. Of course, I didn't know that avrdude could not return good values.
So, now that I know that avrdude can't actually read the fuses through a plain bootloader Arduino, everything makes a little more sense.
I get this:
Signature
1E
95
F
Fuses
FF
DA
FD
CF
Which means "nothing to see here, move along."
Thanks.