Exactly as we predicted, Blizzard has announced the next expansion pack for the world's largest MMORPG - World of Warcraft. Titled "Cataclysm", the pack will see major changes to the world of Azeroth, as well as increased level cap (to 85) and new playable races.

Those races will be the two that were previously leaked - Goblins and Worgen. The Horde get the former, and the Alliance get the latter. Most intriguingly, though, the continents that were released with the original game - Kalimdor and the Eastern Kingdoms - are being revamped considerably.

Some familiar zones - like The Barrens - are getting a whopping great lava canyon down the middle of them. The previously desertified (and often deserted) Desolace is becoming a tropical paradise. The great Orc city, and horde capital, Orgrimmar will be destroyed and rebuilt elsewhere. Flying mounts will also be usable in the old world.

There's a new secondary profession - Archaeology - as well as new class combinations for existing races. People will be able to play as Gnome Priests, Blood Elf Warriors, or even Tauren Paladins. Blizzard is also taking some of the complexity out of the game's stats - attack power, spell power, mp5, armour penetration, defence and block value will be disappearing - rolled into the more primary stats.

For PvP players, there's "Tol Barad Island" - a new Wintergrasp-like world PvP zone. There's also new rated battlegrounds. A huge whack of new raids and dungeons have opened for PvErs, and for the first time Guilds will earn experience points and achievements.

There's no firm release date for Cataclysm, but Blizzard's lead level designer on World of Warcraft, Cory Stockton, has told community site Wow.com that development began before Wrath of the Lich King shipped, and it's slated to be released in 2010, along with StarCraft II.

The last expansion for WoW - "Wrath of the Lich King" - sold faster than any other PC game in history, shifting 2.8 million copies in 24 hours. There's currently 11.5 million active players of the game - more than the population of Greece.

We'll undoubtedly be hearing more about Cataclysm as its release approaches, and will keep you informed.