|New World of Warcraft expansion announced on 8/6|
There have been a lot of negative talk about how Warlords of Draenor has effected the subscriber count. Looking at the curve published on MMO Champion the 1.5 million subscriber drop is bigger than what would be expected, but it is only one quarter. Mists of Pandaria (MoP) had a 1.3 million subscriber drop from between 3 and 6 months after release, so it is only slightly higher. The decline of subscribers after MoP was not as steep I am sure Blizzard hopes the announcement will help stabilize it similarly.
I agree with those who say this is a 10 year old game and there isn't a lot Blizzard can do to change the overall curve. As more people leave there will be a higher peak with sightseers, but it is unlikely many of those returning to see the new content will stay to raid or do other end game content. I would also think there will be a point where the decline will slow because there are also a lot of people who are committed to the game as long as Blizzard keeps supporting it. Even if that is around 2 million people, Blizzard can make a lot of money keeping it a subscription game at that level. I don't see them going Free-to-play but rather ending the game if it doesn't make the profit that makes them want to invest in it. A recent Game Revolution article put the Final Fantasy XIV subscribers between .8 and 1.2 million, World of Warcraft probably still has five times the number of subscribers as the second most popular subscription MMO.
I take Blizzard at their word that they are trying to release content faster. I expect a release in the first quarter of 2016, which would be about 6 months faster than the Warlords of Draenor release. If they can do that, they should get another peak from returning subscribers who are just sightseeing. From there the curve will level out some, but it will be very interesting to see where that seems to happen.