Science agrees that the year 2012 will happen.
We can also confirm that it will be a leap year.

We also know that the present Long Count of the (now un-used) Mayan calendar will come to an end on Dec. 20, 2012 and a new Long Count will begin on Dec.21, 2012 (it is something like a new century in our calendar, except that Long Counts are longer than a century).

The earth's magnetic field has begun to flip. Except that the word "flip" is too strong, as the process takes at least 300 years and could take as long as a thousand. However, the magnetic field (and the Earth's magnetosphere) will continue to exist during the process: we will continue to be protected from charged particles coming from the solar wind and the cosmic rays. The "flip" has nothing to do with 2012.

Some sites also talk of an "alignment" between the Sun's solstice position and the centre of the Galaxy. There is no alignment (the closest the Sun can come to the direction of Galactic centre is more than 5 degrees) and the closest point of approach is not in 2012.

In any event, the Galactic centre is 25,000 years away so that, as seen from the Black hole at the centre of the Galaxy, the "alignment" will be in 25,000 years (or it was 800 years ago, take your pick).

What else do they talk about? Ah yes, the fictitious planet Nibiru. It started off from a weak translation of old Sumerian texts, combined with some loose interpretations of Biblical accounts.

This planet supposedly spends most of its time in the Oort cloud, coming in to our region of the solar system every 3700 years (or so). The "creator" of the legend had its return scheduled for 2085, but recent hoaxers have changed the orbital parameters (easy to do when dealing with a fictitious planet) allowing it to participate in the big 2012 hoax-off.

In any event, this planet is not supposed to collide with Earth. Instead, the inhabitants are supposed to have created us (400,000 years ago) as slaves to mine gold for them. When their planet passes close to us (the legend says), they come and collect the gold we should have dug up for them. They will be disappointed when they find out we lost it all in the recent US mortgage scandal...

Today a DJ saved your mind...