According to today's Activision Blizzard earnings call, World of Warcraft is down to 6.8 million subscribers. That's a loss of 800,000 subscribers since the previous quarter. Once more, the losses are said to have occurred primarily in the Eastern market.
We think it's safe to say a year without any new content carries the bulk of the blame for these losses. Historically, since WoW's subscriber peak in 2011, content droughts tend to see the largest drop in subscribers. It's also safe to say some of the losses will return with the release of Warlords of Draenor, though it's unlikely that all lost subscribers will be recovered -- and it remains to be seen how long recovered subscriptions will hang around.