I have noticed that one thing they haven't mentioned is whether they identified individual cameras of the same model or different models. I've noticed that, at least to the naked eye (I know, they mention that it's not visible to the naked eye, but still) one photograph from my Canon EOS 300D looks about the same as another photograph taken with the same lens, ISO settings, light etc. Also, the lens can be a source of quite a bit of distortion that may or may not affect the noise pattern on the camera. Therefore I'm kinda sceptical about how far you can actually go with this technique. On the other hand, dead pixels (if there are any) can be fairly diagnostic, since the chances of two cameras having a dead pixel in exactly the same place are remote.

Cheers,
cgkanchi