News from Blizzard today regarding their World of Warcraft subscription numbers. Over 1 million in North America and over 4 million world wide!

World of Warcraft Surpasses One Million Customer Milestone in North America
Blizzard Entertainment®, Inc. today announced that World of Warcraft®, its subscription-based massively multiplayer online role-playing game (MMORPG), has reached more than one million paying customers in North America. This brings the total population for Blizzard's critically acclaimed game, the largest MMORPG in the world, to more than four million paying customers. You can read more by checking out this press release.