Basically, some cataclysmic phenomenon is brewing beneath us and the core of the earth is destined to melt away by 2012. The world as we know it would end -- with land masses shifting by thousands of miles, if not sinking at all. Water will once again cover most of the earth. But a chosen group of people will survive in order to preserve humanity ... along with some animals and arts and cultural artifacts and treasures. It's like the story of Noah's Ark but with super cool ships.
You won't have to burn too much brain cells watching this one. It's a disaster movie, people ... the mother of all disaster movies! So just be prepared to take it for what it is -- lots of destructions, lots of deaths, lots of overblown dramatic moments. But it truly is a showcase of amazing CGI effects. So just sit back and enjoy it.
It's just very tiring.