Blizzard Entertainment Tuesday announced that total World of Warcraft subscribers has surpassed 11 million, equal to the population of the entire state of Ohio, according to 2007 census estimates.

The news comes as anticipation builds for the release of the game's second expansion pack, Wrath of the Lich King, which launches on November 13.

"Since debuting in North America in 2004, World of Warcraft has become the most popular MMORPG in the world," Blizzard announced in a statement today. "In addition to being the bestselling PC game of 2007, The Burning Crusade expansion holds the record for fastest-selling PC game of all time, with nearly 2.4 million copies sold in its first 24 hours of availability."

World of Warcraft is unique (compared to most games) in that gamers must pay a monthly subscription fee of US$13-15 per month to play, in addition to buying the game for $30. The MMO has also drawn criticism from disgruntled spouses and researchers for being abnormally addictive.

GamePro awarded four and a half stars to World of Warcraft in 2004, and five stars to The Burning Crusade last year.