Although World of Warcraft is a huge success in massively multiplayer online game market, Blizzard is still striving to seek a way to make a better game. In an interview from kotaku, game director Jeffrey Kaplan was humble for the success which wow holds.

"I don't believe that WoW is untouchable. I completely believe that a game could come out and be more successful than WoW. I'm hoping that we're working on it right now." he said.

"I think a lot of other companies have had great opportunities to do what WoW has done... usually for whatever reason, they miss the mark." Kaplan added.

In the interview, Diablo III lead designer Jay Wilson said he played some other MMOs, such as Age of Conan, Lord of the Rings Online, even City of Heroes. He said the key to MMO success is "not making choices based upon being different, but making choices based upon what's good for your game."

When asked whether Blizzard's next project is the game that finally tops WoW's global success, Kaplan said that at launch, WoW was not what it is today, it's taken the game a five to six-year development cycle, plus two years on Burning Crusade and a year and a half on Lich King. They always make progress, so "I believe it can be," he said.

Recommend to read the full interview: Here