Analysts started likening drug violence in Mexico to an insurgency long before the facts justified the analogy. At first, the comparison was just a clumsy attempt re-describe the dreary old drug war in the hip new counterinsurgency talk the that the young people enjoy. (A similar jargon-shift happened after 9-11, when every bad thing in the world became a species of terrorism.)
However, John P. Sullivan and Adam Elkus (via Narcoguerra Times) make a good case that the facts on the ground are starting to match the rhetoric, thanks in large part to President Calderon's attempt to send the military after the drug cartels on Mexican soil. It's not surprising. Start a civil war, create an insurgency by default.