What would you get if you mashed up Diablo III and World of Warcraft on iPhone?

Don't answer that, because that's not what US iPhone developer Booyah is planning to do. However, the firm has been set up by three former Blizzard Entertainment staffers who had key roles on those two games.

Keith Lee, Brian Morrisroe and Sam Christiansen all left Blizzard to found Booyah, and have just announced that they've secured $4.5 million of financing from VC firm Kleiner Perkins Caufield & Byers' iFund - which previously helped ngmoco get started.

So what is Booyah planning, if not an online swords'n'sorcery epic? Well, the announcement describes it as "a playful life companion that combines the immersive experiences that draw consumers to massively multi-player online games, the interconnectedness of social media, and the power of the iPhone and iPod touch."

Meanwhile, Lee describes it thus:

"Imagine that you could play life by pursuing and sharing your passions. Booyah motivates you and others through a mobile companion, everywhere you go. You become a part of an ever-expanding social experiment, inspiring you to challenge yourself and be better at your life."

The company's advisory board includes still-serving execs from Blizzard and Nexon, too, so it's going to be fascinating to see exactly what form the app takes.