Is 2012 going to happen? Or is it a load of bull?

People have been like freaking out that the world is going to end in 2012. Is this true? Some say it is, some say it's not. I'm confused. Do they even have any proof that this is going to happen, and what is it that would cause whatever to happen? If this were to be true, what exactly would happen? Is it about the planet alignment, the coming of antichrist, judgment day, sun flares, what? Does the mayan calendar really have something to do with it, or did they just like die before they finished the calendar? Do you have a credible site that says why or why not this will happen?