What is really expected to happen around December 21, 2012 is the beginning of a new age; a different energy will reach our planet with positive effects. The Hopis foretold that the change would start when a large blue star appeared. And on the year 2007 comet 17/P Holmes shocked the scientific world with a spectacular eruption which made it the brightest (blue) object in the sky.
“Some have claimed an alignment of planets occurs on winter solstice, 2012, and will cause a catastrophic reversal of the earth’s magnetic field. There is no such planetary alignment on winter solstice, 2012, and even if all the planets did align in this fashion, it would not cause such a reversal of the Earth’s magnetic field. There have been numerous planetary alignments and they have had no effect on the Earth.” Griffith Observatory at: 2012.html
“Several prominent individuals representing Maya of Guatemala decried the suggestion that the world ends on b’ak’tun 13. Ricardo Cajas, president of the Colectivo de Organizaciones Indígenas de Guatemala, said the date did not represent an end of humanity or fulfillment of the catastrophic prophecies found in the Maya Chilam Balam, but that the new cycle “supposes changes in human consciousness.” Martín Sacalxot of Procurador de los Derechos Humanos (Guatemala’s Human Rights Ombudsman, PDH) said that end of the calendar has nothing to do with the end of the world or the year 2012.” Wikipedia Main_Page
More information on 2012 at: http://www.december212012.com/articles/mayan/2012_From_the_Mayan_Elders_Themselves.htm