Ancient cultures tended to view time in a cyclical format, not a linear one. So, the Mayans calendar doesn't actually "run out," as much as it "resets". That it "ends" on the Winter Solstice is indicative of cultures worldwide that paid homage to the Sun. At one point the Mayans actually had three different calendars all running concurrently.
There is a Muslim calendar that ends in 2040, a Jewish one that ends in 2240. As you can see, we have lots of candidates for "predicting the end". But, they are not really ends. These are not the end of "time", they are the ends of "Ages" or "Aeons". The Western world has its own system of the "Great or Platonic Year", made up of "ages" dominated by the Zodiac. You kow, "This is the dawning of the Age of Aquarius"? Well, that also means the "end" of the Age of Pisces. Jesus didn't say he would be with us until the end of "time", he said to the end of the "Age".
So, its probably coincidence that we have an alignment with center of the universe that day, not a calendar prediction. The Mayans were very adept at determining the amount of time it took for the Earth to revolve about the Sun, as the calendar is more accurate than the Gregorian, but the ends of cycles reflect Earth based vantage points of the path of the Sun, not cosmic knowledge. In other words, I wouldn't bank your financial and other future plans on the lack of responsibility you think might befall us after that date. Chances are, we'll see the next day, just as we survived the year 666, 1000, and Y2K.
You'll see it's all a show, keep 'em laughing as you go, just remember, the last laugh is on you, and always look on the bright side of life!