While that is an interesting point you make, and there are an astounding number of superstitious morons who are afraid of that crap, I think (hope) that the majority of people are sensible enough not to take part in a demented killing spree prior to 2012 and wipe out humanity... But, maybe if all the dumbsh*ts afraid of 2012 killed themselves the world would be a better place so in that regard the 2012 myth could be beneficial.
I doubt anything will happen, but there is a massive hole in the earths atmosphere, and there is a solar storm scheduled in 2012, but that isnt supposed to "destroy the planet" Really though the world could end tomorrow and we couldnt do anything about it. This is being made a big deal though, their are several companies, i think one called Vivo or Vevo something like that, that are building underground shelters meant to withstand fire for weeks, and be submerged for days, and earthquake proof.
How many other threads address this topic? I honestly have no idea, but I'll say that some astronomers believe that Earth, the sun, and the black hole at the center of our galaxy will align on that day, possibly causing Earth's magnetic poles to shift, and the outer crust with it. Seems to be what that boy from mars believes.
We've already seen how hyped prophetic armageddon events have flopped earlier, i.e. Y2K, and I can't imagine this surpassing the Y2K hysteria. By 2013 we'll already have forgotten about the whole thing.