How Cataclyms Will Change the Geography of World of Warcraft

With the release of Cataclysm, Blizzard's upcoming World of Warcraft expansion pack, unprecedented changes will occur. The malevolent black dragon Deathwing will emerge from the underground realm of Deepholm to bring havoc to Azeroth, leaving devastation in the wake of his appearance.

Deathwing's emergence will create tremendous, lava-filled rifts in some regions, and destroy other areas completely. Here is a complete list of the areas that we know, so far, will see damage with Cataclysm:
The Barrens will be divided into the Northern Barrens and the Southern Barrens by canyons of lava

Wetlands will be annihilated

Ashenvale will see some damage

Darkshore will be hit, and the Night Elf town of Auberdine completely destroyed

The Stonetalon Mountains will be decimated by fire

The Hillsbrad Foothills will see some damage, with the Alliance town of Southshore possibly destroyed

Silverpine Forest will be hit, with the Greymane Wall being razed

It is also known that the previously ashen zone of Desolace will be flooded with water thanks to damage caused by Deathwing's eruption, and will become green and fertile.

Many other upgrades are being made to settlements controlled by both Horde and Alliance forces. Areas expanded, newly created, or otherwise augmented, include:

Mount Hyjal, in northern Kalimdor, will be opened

Uldum, in southern Kalimdor, will be opened

Gilneas, in the middle Eastern Kingdoms, will be opened

The Twilight Highlands, in the Eastern Kingdoms, will be opened

Tol Barad, an outdoor PvP area in the Eastern Kingdoms, designed after the style of Wintergrasp, will be opened
The Lost Isles, in the Great Sea, will be opened

The Sunken City of Vashj'ir, in the Great Sea, will be opened

The island of Kezan, in the South Seas, will be opened

Shatterspear Village, in northern Kalimdor, will be opened

Deepholm, with an entrance in the previously inaccessible zone north of Stormwind, will be opened

There will be a new Alliance town in northern Darkshore

Warsong Lumber Camp will expand

Zoram'gar Outpost will have a reinforced wall

Orgrimmar will also be reinforced with black metal

The Tauren have added a gate to the entrance from the Barrens into Mulgore

The terrain around the Ruins of Lordaeron in the Tirisfal Glades has been redesigned to accommodate flying mounts

The terrain around Stormwind City in Elwynn Forest has been redesigned to accommodate flying mounts
A new, worgen-centric district has been added to Stormwind City

There are many questions taht remain unanswered about how Azeroth will change in order to accommodate the new content of Cataclysm, particularly the addition of flying mounts to Kalimdor and the Eastern Kingdoms. Hopefully, some of these points of uncertainty will be cleared up by Blizzard in the coming months.