The "2012 doomsday" is a hoax, a fraud, and a con job. It is a cruel and cynical lie being promoted by scammers after money: First they scare people to death that something terrible is going to happen, then they publish books and videos on "how to survive".
These scammers want to sell their books, videos, 'survival kits', and spaces in non-existent "2012 shelters" in Antarctica (although Nancy Lieder has the right idea, and is claiming Hawaii is a 'safe zone'). They also want to divert attention from the fact that they have been wrong so many times before. It's also being pushed by people who are promoting a Hollywood disaster movie which was released in November 2009.
All of the claims of 'predictions' by the Maya, the Aztecs, the Incas, the Hopi, the Chinese (I Ching), Nostradamus, Sir Isaac Newton, Edgar Cayce, Mother Shipton are false: They did not make the claimed predictions. Predictions by others such as José Argüelles, Terrence McKenna, Nancy Leider, Mark Hazelwood and others are contrived pseudo-scientific nonsense.
There will be no sudden 'pole shift', either geographic or magnetic. There will be no 'killer solar flares'. There is no 'Photon Belt'. These are fiction. There will be no 'galactic alignment' or 'planetary alignment' of any kind, and we will not pass through the central plane of the galaxy, and even if these events were to occur, they would not cause any problems for us.