Well, that's four prophesies that say the world will end in 2012.

One of Nostradamus' predictions says something to the affect that the world will be destroyed by a sword from the heavens in 2012.

The Mayan calendar (which is cyclical) runs out in 2012, I believe on Dec. 23, don't remember the exact day anymore.

There's also some Chinese prophesy that makes a similar prediction, though I don't know the specifics of this one.

Personally, I can't wait to see what happens.