This planet will technically always be here but in some very VERY distant future it will probably be a molten ash planet with no living life except maybe tiny organisms that can manage to live in that habitat. As for the human race ending in 2012? no. I beleive the aztecs prediction more then anyone if they mean the end of the human race, the dinoasaurs did suddenly end most likely during one day, or a length of a year (this would mean there was a plague.). Maybe a plague epidemic starts up and whipes out a majority of our population, as well as nuclear warfare? Who knows its only 2007.
The dinosaurs were hardly all wiped out in a day. As a matter of fact many species that were around back then are still around today. Sharks, alligators, etc. Hell dinos could technically still be around if you believe the evolution to birds theories.
Anyway, the leading theories all have to do with asteroids colliding into the earth causing dust and etc to enter the atmosphere lowering the temperatures significantly enough to put dinosaurs who were cold blooded in serious jeopardy as they wouldn't be able to obtain the warmth that they needed to survive.
As to the extinction of the human race. It could all end one day, but I have a very difficult time believing that. Mass nuclear warfare would probably wipe out a great deal of the human population, but I imagine that many remote tribes and peoples would live on.
The same can be said for a plague. Plagues are only dangerous to us because of how dense of a population we are. They would not reach the tribes of the amazon and others who are beyond the reach of humans in general.
As to all life on teh planet being extinguished after it becomes molten ash or whatever you have to remember that life evolves and will always continue no matter what. We as humans may not be the dominant species anymore, but we will evolve over the generations to handle our climates.
That's just my 2 cents though. Some people see humans as parasites. I don't agree with that per say, but I do agree with the comparison in that it will be next to impossible to truly rid the planet of us all together.
