But Blizzard is adding a secondary subscription model that might interest the hardcore: WoW Tokens.
WoW Tokens apparently function similarly to Plex in EVE Online. World of Warcraft players can buy these tokens with real-world money. Each token corresponds to a month of game time. Tokens can then be sold in the Auction House for in-game gold.
Expedient players will presumably be able to play World of Warcraft for free, provided they earn enough gold each month to keep their subscription running. However, it's not exactly the "free to play dream." These types of systems typically benefit high-level players the most--especially ones who sink a lot of time into the game.
World of Warcraft lead game designer Ion Hazzikostas told Polygon that it's mostly a response to "shady third-party gold sellers." Now players who want to spend dollars to earn gold can do so without resorting to some sketchy service with a website that looks like it was made in Geocities.
Even so, it's a huge shift for Blizzard. World of Warcraft has been running on a subscription-only model for ten years, so any change seems relatively huge in that context. Blizzard has not said when tokens will launch yet, except that it will be in "an upcoming patch."
Disclosure: My roommate works for Lewis PR as part of CCP's external PR team. CCP makes EVE Online.