Nice Sci American piece: "Any sufficiently advanced extraterrestrial intelligence is indistinguishable from God."
Ergo, the probability that an ETI only slightly more advanced than we are will make contact is virtually nil. If we ever do find an ETI, it will be as though a million-year-old Homo erectus were dropped into the 21st century, given a computer and cell phone and instructed to communicate with us. The ETI would be to us as we would be to this early hominid–godlike.