The FAQ over at worldofwarcraft.com has been updated with a few new items. One of which is the pricing of WoW.
“Will there be a monthly fee to play the game?
Yes. When you purchase World of Warcraft, you will get a one-month free trial subscription to the game. At the end of that month, you will have to choose from three subscription plans to continue playing the game: a month-to-month package at $14.99 per month, a three-month plan at $13.99 per month, or a six-month plan at $12.99 per month”
Go check out the rest of the FAQ: http://www.worldofwarcraft.com/info/faq/