Mists of Pandaria will be on sale for $9.99, and it comes with a free 60-day game card. In addition, StarCraft II: Heart of the Swarm and Wings of Liberty will be on sale for $19.99 each, and purchasing either of those will net you a 60 day game card. The World of Warcraft Battle Chest will be on sale for $4.99, but it does not include a game time card with the purchase.
For those looking to get started with WoW, this does come out to a pretty good deal -- you can get the Battle Chest and Mists of Pandaria for $15, and get a 60 day game time card free as part of the purchase. Or if you happen to have a friend interested in StarCraft, you can pick up the game for them, and keep the WoW game time for yourself. GameStop's Black Friday ad should be available on their website soon -- those looking for the official ad can visit their official Black Friday page and sign up to be notified once the ad itself goes live.