If you are familiar with the show and I'm judging from the posts here that many of you are not, you would know that the writers do a lot of research whether it be fringe science, the paranormal, cryptids, etc. Books and a few TV shows about the Mayan "end date" have been around since the late 70's. Legitimate reports, personal accounts, and even fairy tales were a few of the many sources that the writers called upon and anything 2012 related was probably used.