What will happen on December 21, 2012?

For several years it has been circulating the belief that something important will happen this coming December 21, 2012 at 11:12 (UTC), which coincides with the December solstice.
Where does this date? From a Mayan calendar known as the "long count calendar" which lasts for 5125 years.
The big question here is: what will happen on December 21, 2012?
Obviously there are various theories. Many say that the human race will experience a positive transformation at the physical or spiritual level and with this transformation will come a new era of welfare. Of course that never fail those who believe that the coming end of the world (again) or a major catastrophe will happen, either that Earth will be swallowed by a black hole, a meteorite will collide with the planet, we destroy a Solar storm, etc.
According to some of the current Mayan leaders, nothing bad will happen on this date. In fact it was discovered also a Mayan calendar latest about 12 centuries ago that lasts 7,000 years.
In short: the contradictions abound.
What is the purpose of this post? Focusing on December 21 from the side of the technology .
Today, what is one of the most technology institutions in the world? NASA of course. What they say about it? As seen by the network in recent days, in a statement released by the space agency has denied all rumors about global catastrophes, end of the world and any similar tragedy could happen.
In recent years, the level of people who believe in this kind of tragedies and events has dropped considerably, but still having a large impact on the world of Internet, especially on sites like social networks, video portals, etc..
Astronomers have rejected the apocalyptic events repeatedly, always saying that they have no real scientific basis protect them. NASA itself has said that the fear of 2012 is similar to the fear of doomsday in 1999.
Two of the phenomena that seem to get much are the terrestrial geomagnetic reversal and an alien invasion. For the first case, there is no scientific evidence that points to magnetic field reversal of the Earth will occur in 2012, but this phenomenon is estimated it could be seen in about 5,000 years. Regarding the arrival of beings from another world, is something that has been very popular in the general culture for decades. There are many series and films that predict the end or the conquest of land by beings from other planets, but so far governments and major companies say they have no clues about it and continues to deny the existence of beings from other worlds Earth, but a few days ago Russian Prime Minister made ​​a statement that caught the attention of the media.
In short: we have no evidence that anything will happen on 21 December, so that everyone, of course, is free to believe in whatever they want.
And you, do you think something will happen this December 21? If so, which one phenomenon will witness mankind?