If I haven't stated it clearly before, let me do so here: the disaster hype around 2012 is a bunch of muddleheaded nonsense. The Mayans themselves didn't believe that some great disaster was due when their "long count" calendar wraps around; it was just time for a big party, same way 2000 was for us.
And no, there will not be some grand alignment with the center of the galaxy on December 21, 2012: the Milky Way is too blobby for the idea of a visual center to be meaningful, and the winter-solstice sun will never actually eclipse the galaxy's central black hole (which shows up as a point-like radio source) -- it doesn't even make its closest alignment in the sky with that black hole for another 200 years, not that this means anything anyway.
So there's no big deal in 2012. And...it seems that maybe the Mayan calendar doesn't actually wrap around in 2012 after all. A new review of the conversion of the ancient Mayan calendar to our Gregorian one suggests that it may be off by as much as 50 to 100 years. Gerardo Aldana, associate professor at UC Santa Barbara, looked at the arguments anthropologist Floyd Lounsbury made in support of the so-called "GMT constant", and found them wanting, throwing the conversion into doubt.
So it might not wrap around until decades from now -- or it might have already happened decades ago. (Rather than taking this as a debunking, I'll bet that at least one 2012 disaster entrepreneur will try to take advantage of this when the world fails to end in 2012, and start hyping some other date for the apocalypse.)
Now, some folks think that 2012 is a convenient time to think about making a change -- just as with a New Year's resolution, there's actually nothing special about January 1, just a social convention. Fine, great, and wonderful: just don't assign unwarranted supernaturalism to the date.
Me, I'll be turning 42 in 2012, and as a big Hitchhiker's Guide to the Galaxy fan that means more to me than any old Mayan calendar. Also, 2012 fits the Law of Fives: 2 + 0 + 1 + 2 = 5, so as a Discordian it's significant. But Mayan prophecy? Astronomical disaster scenarios? Poppycock.