DS,
We have a discussion going in the non-U.S. area at the moment which includes TT vs. TN-C-S grounding systems.
Many homes in Britain and Europe have exactly the situation you describe: The buildings sole ground connection is a rod, with no bonding to the neutral. The overall impedance of the circuit in such an installation means that even a direct phase-to-ground short doesn't result in enough current to open a normal OCPD, so everything has to be GFI-protected.
Grounding just to a rod without such protection is practically ineffective, as a ground fault will just result in a couple of amps (or less) flowing back to the supply through the earth and the frame of the faulty appliance rising to supply potential.
Such installations are banned in America by the code section BJ quoted above.
