From David Morrison of NASA (and yes, I know NASA is 'in on it'.)
A: There is no factual basis for the many Nibiru stories. This Internet chatter originated from the claim by Nancy Lieder that she was warned about this planet by aliens from the star Zeta Reticuli. In the absence of real information, however, people speculate and embellish this fictional story. One such addition is to link Nibiru with Planet X, a term used for many years by astronomers to refer to any unknown planet that might exist beyond Pluto. Far from being a real object, this term indicates an unknown or undiscovered object (that is why it is called X). Another false link is with Eris, the largest of the dwarf planets recently found beyond Neptune, designated 2003 UB313 when it was discovered in 2003. Before Eris was given its formal name, its discoverer, Mike Brown of Caltech, informally referred to it as Xena, a word play on Planet X. The name Eris was officially adopted by the International Astronomical Union in 2006. However, this has nothing to do with Nibiru. Nibiru is supposed to be a large planet on a highly elliptical orbit with a period of 3,600 years, which comes onto the inner solar system and will disrupt Earth in 2003 (the original claim) or 2012 (the current claim). Eris is a dwarf planet (smaller than the Moon) with a period of 557 years, currently far beyond Neptune or Pluto at a distance of about 10 billion miles. Its orbit will never bring it into the inner solar system; the closest it will come, in about 2255, is 4 billion miles. Eris does not match the fictional object Nibiru in distance, orbit, size, or any other property, and it does not threaten Earth in any way. The other items you mention from the Internet are untrue. Neither Pluto nor any other transneptunian object is deviating from its normal path. Time is not speeding up, and the days are not shorter. You know as well as I do that there are still the usual 24 hours in the day, not 16! Please dont be scared; the entire Nibiru story, as well as any concerns about Eris threatening Earth, are a hoax, nothing more.