With the World of Warcraft subscriber base climbing to an impressive 11.5 million just last December, it seems there's no stopping Wrath of the Lich King from conquering everything he sets his eyes on. That is, until the almighty warlord ran into a force much greater than him - the Chinese government. To this day, the extremely popular MMO has yet to receive a license from the Chinese government to operate in mainland China.
The Chinese government has already rejected two applications by the second expansion due to content that did not meet requirements, such as a city raid and skeleton characters. The submitted version also did not feature the popular Death Knight hero either. World of Warcraft is still undergoing changes to meet requirements until it's deemed acceptable by the Chinese government.
Blizzard is still trying to meet their standards, and at this point, there's no telling when the Lich King can successfully raid China.