A NASA astrobiologist, David Morrison, is providing answers about Nibiru destroying the Earth.

He also has an extensive FAQ with a good amount of dry wit

I note that my desk calendar ends much sooner, on December 31 2009, but I do not interpret this as a prediction of Armageddon. It is just the beginning of a new year.

So remember, NASA's official position is that we will still be around in 2013.