Additionally There will be an average of 18months between each add-on, giving the game an estimated expected lifespan until 2013. This will allow blizzard to have overlap between World of Warcraft, and it’s upcoming MMO(s) of 2-3 years.
- Burning Crusade – Outland – 2 new races – lvl70
- Wrath of the Lich King – Northrend – 1 new class – lvl80
- ?? – Undermine / Kazan – ?? – lvl90
- ?? – Maelstrom – ?? – lvl100
expect races such as the goblin (horde), Murloc (alliance), and recently announced Tuskarr (horde) races to become playable at some point over the latter two add-ons, with a potential for a race to swap sides from horde to alliance.
Note, this post is all speculation.