We've known for some time that are hard at work on a brand new, top-secret project, and director Jeffrey Kaplan has told MTV that he is involved in the new game.

The new 'next-gen' MMO remains very much under wraps, but Kaplan did say the secret of World of Warcraft's success is in part down to the art style.

"A lot of it has to do with art style, too," Kaplan offered.

"Are you going for realism or an inviting world? And once you learn those lessons, I think any type of [intellectual property] can survive. I’m shocked we haven’t seen more sci-fi, near-future, post-apocalyptic, historical MMOs; there’s all these completely different fantasy settings beyond the traditional high fantasy ones."

Kaplan wouldn't be drawn on the setting of Blizzard's new MMO, however.

By Luke Guttridge