Ok, this thread is a few months old but it is an interesting topic to discuss. Let me preface by saying that I have studied Mesoamerica at university level so I know a thing or two about the Maya, and I would like to clarify a few things.
Ok, first of all, the Maya calendar. Does it really 'end' in December 2012? Well the truth is, we don't really know. During the Spanish conquests of America the Conquistadors fucked up a lot of poop, and many documents that would have helped in the translation of time from the Maya calendar to our own were lost. 2012 is a popular theory, but it is far from certain. Secondly, the calendar is inherently inaccurate for long measures of time. It is a cyclical measurement system, which means it repeats itself exactly, and therefore does not adjust itself in relation to the gradually changing astronomical periods (for example we have a leap year to compensate). Because of this, the Maya calendar is in fact way out of line with astronomical events and is not nearly as accurate as some of you seem to imagine, and I therefore conclude that the Maya could not possibly have predicted astronomical events that far into the future. Thirdly you have to remember that this whole 'start of a new era' thing on which the significance of 2012 is based is firmly rooted in Maya religion in which life and time is cyclical in nature. But to put it bluntly these people believed some crazy butt poop. (Human sacrifice anyone? And have you read their creation myth?) If you believe in the significance of the end of the long count you might as well believe in all Maya mythology.
Lastly, there is one mistake many of you are making that leads me to believe you are not as educated on this topic as you might like to think. And that is "Mayan". The only time the word Mayan is used is in reference to the language of the Maya people. The correct demonym for Maya is 'Maya', as in 'Maya calendar' or 'Maya artwork'. It sounds nitpicky but really it's a pretty basic thing to be getting wrong.
