Will the world end on 21st December 2012?

Yes, no or maybe.
Going to be fun finding out.

I already have a reservation on the Ark.

Not really end, but it will change greatly, those who are not part of the New World Order or a expert on AMHD are doomed but those of us who have been picked to survive will meet before this date to be escorted to a secure place to wait out the on coming doom.

There have been about 514 Leap Years since Caesar created it in 45BC. Without the extra day every 4 years, today would be July 28, 2013. Also, the Mayan calendar did not account for leap year…so technically the world should have ended 7 months ago.

I'd have to say that for the Mayan ;the world ended a tad earlier .