Note to all: To quote the wise sage of ages past (Elmer Fudd): "Be vewwy, vewwy careful". This topic can be quite sensitive and can have both political and religious aspects - neither of which have any place on this forum. I have already edited the first post slightly, and at the first hint of the thread derailing I will remove it in its entirety.
I've lived long enough to know there's at least one of these "end of the world" or "beginning of the new age" predictions every decade - most recently the Y2K bug. Every time the prophets of doom say "whoops, tiny mistake in the calculations", move the date forward a decade or so and carry on making money from the gullible.
As to this specific prediction...
The whole 2012 thing is extremely thin, based on things that can be interpreted dozens of different ways and some pseudo-science. Instead of just looking at the websites that all predict the same thing (and link to each other as evidence of their claims, in a massive circle-jerk), take a look at the other side too, there's plenty of solid evidence against and a lot of stuff pointing out the shakiness of the "evidence":
http://www.nasa.gov/topics/earth/features/2012.html
http://www.nasa.gov/topics/earth/features/2012-guest.html
Oh, and the Pentagon construction thing... You think that might have anything at all to do with an aeroplane crashing into it on 9/11? I would imagine that not only did it cause damage that needed repair, but that it woke them up to the fact that maybe they should upgrade a bit. No idea if I'm correct or not or what the official reasons given are, but it seems logical.
my countless nights of sitting in front of my computer 'till 4 AM, only to sleep it off in Math the following day, has proven invaluable to me.
Ummm... ??? So you're short on sleep when you're reading this stuff and are neglecting your studies as a result? Doesn't seem like a fair trade to me, let alone invaluable.