Mayans. We ignored them until 2010. Then when the New Age Industry ran out of Memes, someone found them again. Basically, according to one interpretation of their calendar, a Great Cycle is supposed to end about Dec 21, 2012.
If you ask me, we've seen accelerating news cycles for some time now - and I think a global data-breach of, say, all of Google's data could spawn the End of the World As We Know It.
We know there's a brewing showdown between "Anonymous" ("whoever they are, all of them"), and the US Govt. The Feds are just biding their time to plan the Politically Perfect moment - it's under 2 years from now.