Thoughts? Yes, it's all crap.
Einstein didn't write anything about pole shifting; he wrote a foreword to a book that dealt with the subject... before plate tectonics were even a theory.
Mayan could predict the end of the world in 2012, but failed to see the collapse of their own civilization? Bzzzzt. Thanks for playing.
Nostradamus was a con man who realized the simple truth that if you write your predictions in a vague, image-laden language, people will see all kinds of things in them. Just like the daily horoscopes who are so vague that just about anyone of them (for any sign) can fit your day.
Or those cold-readers who claim to speak with the dead, but somehow only hear the letter "J" all the time. Is the afterlife a game of Wheel of Fortune, or what? Can't they buy a vowel?
The Earth aligning with the galactic center? WTF? Aren't we always aligned with it? If you have two points (the Earth and the galactic center), there's only one line you can put through both of them... we're always in line with it.
Those alignment stories sound great, but gravity's pull over vast distances, even for a giant black hole, is trivial. The moon's pull on us is much greater than the galactic black hole, and it's not ripping the Earth apart anytime soon.
One thing that's very odd though, is that all those "end of the world in 2012" proponents have 401Ks and retirement funds that are expected to pay off way after 2012. If you really expect the world to go belly up (equator North?) in 2012, shouldn't you just be living it large until then?