No, this isn't exactly about "OMG THE WORLD IS ENDING" Mayan calculator prophecy nor about the movie, but rather the fact so many people out there in doomsayer communities believe this. I've been thinking that even without a cataclysmic event being imminent on that date, the potential hysteria could inadvertently lead to the very thing that is feared. Even if it doesn't reach an apocalyptic scale, imagine all the ridiculous behavior that will emerge as the time approaches to within a month of the date. Look at Y2K for instance, and how people reacted to that. Well imagine that but amplify it, due to the religious/social significance this date has in culture.
This scenario does concern me, because from what I see, it's entirely plausible too.
So the question is, is it actually possible that a serious event could emerge on December 21st, 2012, but not because it was foretold or predicted, but because people want to believe in it and make it a self-fulfilling prophecy?