Planet X: Fact or Fiction?

I remember back in the late 80's, there was an announcement about the discovery of a new planet, dubbed Planet X. Many now know this planet to be the planet Nibiru, which is said to be the doomsday planet. It's orbit is scheduled to cross with Earth's orbit in the year 2012, and will cause great calamity and catastrophic events that will ultimately lead to our demise. My question is: Does NASA and other distinguished organizations recognized by World Leaders acknowledge this claim, or is it as simple as a cover-up, or worse, a collaboration with some unknown species with a hidden agenda? What are your thoughts?