Sony reckons that World of Warcraft's success will eventually be dwarfed by an MMO that caters to the Facebook crowd.

Speaking to to mark the ten year anniversary of Sony's EverQuest, lead designer Ryan Barker said that the game to knock Blizzard's Warcraft, which enjoys an eye-watering 11.5 million monthly subscribers and is currently the world's largest MMORPG, off its throne may be "something totally different that we haven't even thought of yet".

He said: "At some point someone will dwarf those numbers with a game. If we can get passed some of the barriers that are keeping people from playing with their friends, just because their friends happened to start the game before they did, and maybe started on a different server or whatever, if we can start to get rid of some of those social blocks, I think it can get even better."

Barker, who admits he is "constantly thinking" about what shape this all-conquering MMO might be, suggested social networking site Facebook as inspiration, saying "Facebook doesn't care how long you've been on Facebook".

"Things like that show us that there are a lot of people out there that are interested in being involved in an internet community, especially with all the apps on Facebook, in playing casual games. At some point someone's going to do an MMO that really caters to that group, and is going to have a billion subscribers or whatever. There's another ceiling somewhere that we haven't hit yet."

Barker said that the game may not follow traditional fantasy MMO conventions, and that the genre "may almost be an afterthought".

"It's mostly going to be how the social interactions work. There is still somewhat of a stigma with the fantasy genre. It'll be some weird mix of something we haven't seen before. A lot of the standard video game genres I don't think will have the breadth of appeal that would be necessary for something like that. It might not even be a game world per se; it might be something totally different that we haven't even thought of yet."

What do you think readers? Will an MMO ever dwarf World of Warcraft? If so, what kind of game would it be? Let us know in the comments section below.