The Mayan calendar just ended at 2012, there was no prediction about the end of the world. It is just like an odometer rolling over, there is only so far it can go.
HOWEVER. The Earth VERY slowly changes it's tilt (currently at 23.5 degrees) and it just so happens that it reaches it's max tilt(24 degrees) the year is 2012.
Therefore, I can lean both ways.