There's a thread for this in the philosophy section but the world isn't going to end in 2012. We aren't that special. I believe a major event that will change the world will happen but the end of the human race is a long ways away and the end of the earth is even farther
When the sun uses up almost all of its fuel and begins expanding. The only thing keeping it "small" is its own gravity, the fusion reactions providing the heat/energy keeps it the size it is. When the fuel is almost gone the hydrogen is almost all converted to helium, and the big hot ball gets a LOT bigger. It will expand beyond the oribit of the Earth, but since it will take billions of years to happen, I don't think we have to worry too much. I don't think of "the world" involving only humans. I'm talking about the TRUE end of the world. No Armageddon, no asinine 2012 bullshit, just nature taking its course as it has been, is, and always will be doing. http://www.mhhe.com/physsci/astronomy/uspeak/sept_00_uspeak.mhtml
[ame=http://www.youtube.com/watch?v=Hz86TsGx3fc]YouTube - '2012' Trailer HD[/ame] I don't know where or when but all I know is that if it's apparent that it's going to happen, I'm throwing a huge fucking party and getting as high and drunk as I can, with as many of my friends and family .
Lets keep this realistic eh? I'm leaning towards the Planet X thing like Mr. Fox pointed out or a Asteroid just smashes earth into a million pieces, that or a Solar Burst like the one in the movie "Knowing."
I except it to end when jesus returns to earth to claim his followers. I expect to see everyone brought down to their knees to show respect for the god they denied so long. Everyone one will be in shock. Theres no religion that has everything right so it's gonna be an eye opener for everyone. If it ends with just a giant solar flare or whatever (off that movie) then so be it...no escaping miles of flames burning in the thousands.