The sad thing is - nobody predicted a tsunami on boxing day or the planes hitting twin towers and yet for thousands of people these kind of events were and continue to be their own personal doomsdays and major traumas for their families.
I don't really think anybody is qualified to say this sort of thing will happen, at this point in time, and kill this many people - with the benefit of hindsight sure, but for real and in advance - just not possible.
The Mayans lived before science - in the kind of times when thunder and lightening was taken to be god speaking or punishing people - we can't live our lives in fear of these vague stories of old.
Even our top scientists who study volcanoes for their whole lives, can't tell us when an eruption will happen and there are so many real issues to worry about - don't stress about stuff which might not even happen - save your well being for stuff that will happen and remember its all possible
Like some others have said, if it is going to happen we'll all have to live or die with the consequences then - just enjoy life and remember to tell the people that you love how much you love them whenever you can.