I'm doubting a world ending extinction level event will happen on that date. There are a lot of theories floating about regarding the Mayan Prophecies, as Ross said, it's all about interpretation. One person says this, the other says that.
From what i gather after reading some things about it, is that they are prophesising about a time of great change, which could mean just about anything really.
Although, you only have to look at whats going on around the world today to see that great changes are happening already.
Aurora :)