The world will not end on December 21st, 2012. The government is sure of it and so is NASA. In fact, NASA is so confident that the world will not on that day, that it has already published the December 22nd, 2012 ScienceCast video explaining why the world didn't end the day before. Heady.
So here you have it, a sober, reasoned future explanation of why the world didn't end on December 21st, 2012. Very clever, NASA, but if you're wrong about this, no one will be around to know it. [CNET]