The rise of the free-to-play western MMO hasn't gone unnoticed at Blizzard, developers of World of Warcraft, the dominant western subscription MMO. Speaking to PC Gamer at their studios in Irvine, California, World of Warcraft's lead designer, Tom Chilton, explained that "at some point, it may not make sense for us to have a subscription fee."

Tom was speaking about the rapid expansion of free-to-play games in the west, and the terms under which Blizzard would consider a similar model for World of Warcraft. In the last year, classic western hardcore online games such as Lord of the Rings Online, Company of Heroes and Dungeons and Dragons Online have all embraced a free-to-play model, where microtransactions and item purchases are a substitute for a traditional subscription fee.

Yet Tom doesn't think those games have gone free just to compete with World of Warcraft. "I feel like they're doing that to compete with other games that are on a similar subscriber level to what they were at. I imagine that when one of them went free to play it cannibalized some of the other subscribers. I can definitely imagine that being the case with World of Warcraft. If another game comes along and blows us away it may not make sense for us to have a subscription fee. Or even further down the line, when we have another MMO out."

While the western view of World of Warcraft is that it's a subscription-only MMO, the Blizzard team have long experimented with alternates to a traditional subscription to remain competitive in different markets. Multiple micro-transaction items are available to buy for the most committed World of Warcraft players - including shiny star horses, and warrior panda pets. In Korea, the game is sold purely via subscription fee, with no boxed product available. And Korean World of Warcraft subscribers will get to play StarCraft II for free, too. In Russia, StarCraft II is sold in small monthly instalments - a salve to a market where piracy is rampant.

Don't cancel your subscription just yet though: WoW isn't going free-to-play in the near term. When asked if Blizzard were actively considering the implications of a free-to-play model, Tom played down the idea of the game switching over right away. "We're not spending a lot of time thinking about it. It's not something that's a reality for us in the near future."

We've got much, much more on World of Warcraft: Cataclysm in the new issue of PC Gamer , on-sale tomorrow. We'll be posting more Cataclysm news, impressions, and interviews over the coming week.