We won't die from 2012, its just communication will die in half of the world.
Nothing remarkable will happen in 2012, and nothing wholly remarkable will happen with this asteroid.
We're well equipped to fly something into it, that's all it would take, simply change the course.
And, if you did blow it up, wouldn't it burn up in the atmosphere? What is all this junk about it raining stuff? It'd have to be in rather large pieces for it to get through.