Speaking at Activision's earnings conference call last night, Blizzard president Mike Morhaime revealed that the developer is planning to hasten development on World of Warcraft expansions to reduce the amount of subscribers lost--the "churn" rate--once the new content has been exhausted.

"What we have seen so far is that people have been consuming this content very quickly and so the subscriber levels have decreased faster than in previous expansions," Morhaime said, speaking about WoW's latest expansion Cataclysm, which was released in December 2010.

Morhaime noted that WoW now has "more than 11.4 million subscribers worldwide," down slightly from 12 million in October 2010. As ever with these figures, do bear in mind that Blizzard's definition of a "subscriber" isn't strictly limited to people who themselves pay subscription fees, also covering active accounts in Internet cafes and the like.

"As our players have become more experienced playing World of Warcraft over the many years, they have become much better and much faster at consuming content. And so I think with Cataclysm, they were able to consume the content faster than with previous expansions," Morhaime explained. "But that's why we're working on developing more content. We launched our first update last week and we have another update that's already in test."

"The response that we've gotten so far from players has been very positive and we really think that we need to be faster at delivering content to players. And so that's one of the reasons why we're looking to decrease the amount of time in between expansions."

Morhaime noted that "we're not ready to talk about the content expansions at this stage but we are looking at ways to speed up the development process."

WoW's first expansion, The Burning Crusade, was released 26 months after the MMORPG launched. Wrath of the Lich King followed 22 months later, then Cataclysm arrived 23 months after that.

Morhaime also addressed the effect WoW latest competitors, which include DC Universe Online and Rift, have had on subscriptions.

"We knew that this year was going to be a year where we faced new competitors. It isn't the first time, though, that we have strong competitors enter the MMO market," he said. "What we have seen in the past is, we tend to see our players leave for some period of time, perhaps try out the new MMOs, and then good percentage of them historically have returned to World of Warcraft. And so, so far I haven't seen anything to indicate that this will be different."

For the distant future, Blizzard's also working on a new, unannounced MMORPG codenamed Titan, based upon a new IP.