Recently PC Gamer UK releases some new infomation about the upcoming World of Warcraft: Cataclysm expansion. Such as raids, mechanics and something more. There are rumors about the major plotlines in Cataclysm, as well as details about the group and raid instances that will be available at launch.There are some details follow as:

Inner-Horde relations

After assuming command of the Horde, Garrosh labels Cairne a traitor and executes the Tauren Leader. However, this does not seem to be the end of his involvement in Cataclysm and his seeming demise is linked to the greener, lusher Desolace.

Garrosh will throw out most of the Blood Elves and Forsaken from Orgrimmar.

Warchief of the Horde

Thrall will become the next Guardian of Tirisfal. However, Thrall will merely 'leave Garrosh in charge' though this does not stop Garrosh from declaring war on the Alliance and fortifying Horde outposts and cities.

Deepholme

It is possible that the Alliance and Horde will be involved in a major battle within Deepholm.

Airships will battle in the gigantic caverns al a Icecrown style.

The area will also cater for flying mounts.

Blizzard always said that they would come back and use Grim Batol and Uldum-but those areas had gone unused for so long that many assumed that those plotlines would simply go unresolved. The BlizzCon 2009 Deepholme was announced as a level 81-83 dungeon, presumably 5 player. If this area turns into a major plotline with an epic clash between Horde and Alliance who knows what it might turn into.