http://www.nasa.gov/topics/earth/features/2012.html
This page about the claims about 2012 are false and even if there was a planet X NASA would had been tracking that for years! So all of these claims are not true here's what may happen during this proclaimed doomsday
- Magnetic Poles may shift
- Some Solar Flares may hit
- May be a chance of a Solar Wind
So there you have it I hope you have a nice warm or cold day on Decemeber 21st and have a Merry Christmas and a Happy NEW YEAR!
Besides if it was the end of the world, the only way to make it end was the sun to grow and eat up the earth as a tasty snack and we'll no longer be on the Solar System.