Yep, the 21st century is well under way. Before you know it the current hundred count is going to be a teenager:- Hopefully a less stroppy one that last year which resulted in the full blown tantrums of World War I (If this is the case, surely World War II was caused by the century's early onset of a middle aged crisis but now the metaphor is being stretched beyond logical comprehension) and the Russian Revolution.
Some people - more than a sane world should contain - believe that the Mayan calender stops at a point comparable to the later end of our own 2012, thus marking the end of civilization due to one or several cataclysmic events occurring, from major flooding to a previously undiscovered planet crashing into our own like Dawn French outside a pie shop that closed early.
The idea that this particular year will be humanity's last is not ridiculous in itself:- After all ANY given year could be our big finish. However one has to doubt that if we do get drowned/blown up/shipped off to become alien sex slaves, it will be because some chaps in strange nappies and animal hats declared it over five thousand years ago.
Many people who are concerned that the Mayans were spot on the money seem a little uninformed, citing sources such as 'Jen from works' cousin' to another awful Roland Emmerich weather-porn movie.
The Mayans created several calenders denoting what are now academically referred to as the precalassic, classic and postclassic eras. The ending of these basically meant the people of pre-Colombian America considered a particular period of time the end of a cycle or 'world age' and the onset of another.
The point? Don't stop paying buying those lottery tickets and stocking up on booze and shotgun shells just yet.
The idea that the world is going to end because a timetable ran out is a bit 'pie-in-the-sky'. However if you still find yourself a bit concerned then remember that it's quite likely that the Mesoamericans only stopped bothering making calendars because builders of the day kept complaining that there were no tits on them.