The 2012 thing is the earth (And the whole solar system) going into the galactic plane.

All this is is the moon is basically between earth and the center, or vice versa, or something along those lines. What they are trying to suggest, in non-mumbojumbo terms, is that the radiation and cosmic particles streaming out from the central area would somehow be focused by this alignment into a more intense dose. Perhaps in some process similar to using starts as magnifying lenses for astronomy. So if you have more radiation or particles flyin by, there's more chance a couple might collide with some atoms in your brain, which could cause it to go haywire for a while if some neurons gets out of wack.

Good times.

Dont freak out though, the likelyhood of that happening is quite low indeed, I would imagine