I had two things that struck me. In this episode there were no shots of land masses that I could make out. Also, the ruins didn't seem to match the landforms of New York assuming that was supposed to be New York.
Second, would it have been possible that the Cylons had there own Cold War Nuclear era and did it to themselves as humanity had almost (and still might) vaporize themselves?
It's just too bad that they don't run into another race of beings or a Federation Star Ship.