What is the storyline for World of Warcraft Cataclysm

Deathwing has been released from his long imprisonment, and has laid waste to the world of Azeroth. In the upheaval, many changes occur in the societies of its people, as they try to cope with the changed world.
The Elemental Lords break their imprisonment and begin to exert their influence while whispers abound of another Old God, the corruptor of the Emeral Dream, who might be responsible for this.

In the meanwhile, the Cataclysm has robbed the Goblins of Kezan of their homes, and they now seek refuge with the Horde. The feral Worgen, infected citizens of Gilneas, rally to the side of the Alliance as their home is under attack by the Forsaken.

And in the end, Deathwing looms. One day he must be destroyed to prevent his predations from shattering the world even further...