Put it this way:
Let's assume the Mayan calendar DID predict the end of the world.
Let's also assume the Mayans wrote nothing on how the world would end at that time (if someone can locate evidence that the Mayans DID believe it was the end of the world, and wrote down the wrath of whatever for that day, please let me know).
Assuming no religious crossover (that would be an affront to most religions anyways), we can disregard demons eating the planet, or the awakening of Cthulhu, or anything of the kind.
This leaves us with the assumption that the world would end from a natural cataclysm.
So let's see here:
Have astronomers predicted a passing asteroid/any other astronomical danger that day?
Is the LHC going to open a black hole?
Will we manage a Verneshot?
Are the world's nations on the verge of nuclear war?
These are the only ways I can think of off the top of my head that would end the world. Since it's ridiculously hard to hide stuff from the public nowadays (remember, "There's Water On The Moon" was leaked by Twitter, of all things), we can assume that verge of war/astronomical disaster wouldn't be properly under wraps, so unless it's been leaked while I wasn't looking, we can rule those out. The LHC shouldn't be opening any black holes any time soon, seeing how we've already done the more dangerous experiments, so we'll disregard that.
That leaves us with Verneshot, which is a supervolcano going off so hard that it launches a huge chunk of earth into near-orbit. The only supervolcano that is scheduled to go off any time soon is Yellowstone, which quite frankly isn't strong enough to cause a Verneshot. It would hurt the US and Canada badly, but it wouldn't be world-ending.
So no, I don't think the end is nigh.
