April, 2012 is entirely different. It is based on a Mayan prediction, or rather suggested prediction, that the world will end on December 21, 2012. Here is a site with information about 2012. http://photoraps.blogspot.com/2009/09/2012-end-of-world-proof.html
The meteor situation is completely different. Apolis is supposed to pass the earth in 2029, but because of gravity there is a 1 in 45,000 chance of the meteor hitting earth in 2036. The meteor is 390 m wide.
There is a second meteor that could possibly hit the earth in 2019, although I don't know very much about that one.