[More info] Blizzard today announced the first paid content update for Hearthstone, titled Curse of Naxxramas, visiting a classic location from the Warcraft lore. A single-player campaign with 5 wings, the first wing of Curse of Naxxramas, The Arachnid Quarter, will be available free for all.
Curse of Naxxramas will feature 30 new cards and several bosses, with the completion of each wing will rewarding players a guaranteed new Legendary card. Scheduled for a launch simultaneously for PC, Mac and iPad, the launch date and pricing for the 4 wings will be announced at a later time.