Yesterday, World of Warcraft co-creator Jeff Strain took the lid off his new project, an ambitious "online world" zombie-survival game codenamed Class3 coming exclusively to Xbox Live Arcade.

Whether it succeeds or fails, it's an intriguing prospect and one that many PC and PlayStation 3 users might feel sore about missing out on.

So why did Strain's Undead Labs studio choose to team up with Microsoft Game Studios rather than go multiplatform?

"We talked to everybody," Strain explained to Eurogamer.

"This was not a religious decision for us. We love the PlayStation 3, we love the Wii, we love the PC. What it came down to was that we found that Microsoft, as a publisher and custodians of the Xbox, are very excited and aggressive about the online future of the platform.

"They embraced our vision of where we wanted to go with this and just got in there and said 'Hey guys, let's get in there and make this happen.' That gave us a lot of confidence.

"Also," he added, "there's the very real aspect that we're here in Seattle, and they're over in Redmond. It's a 15 minute drive. When you're dealing with a publisher-developer relationship, you can't really discount how nice that makes things in terms of being able to get together and work through issues."

Despite the game's proposed MMO elements and Strain's background in desktop staples Warcraft and Guild Wars, there are no plans to bring it to the PC either.

The Undead Labs founder explained that he sees Class3 as an opportunity to bring the genre across to a console audience. The only way to do that, he argued, is to build it from the ground up with the console's strengths in mind, rather than porting across a PC experience.

"We believe starting from the ground up is the right way to make a full online world experience that feels at home on the console platform," he insisted.

"But it takes you having to take a deep breath and leap, right?

"Right now the market for online world games is on the PC side of the fence and to say to yourself I'm going to make this investment and make this kind of game and not make it for that platform – that's not a trivial undertaking. One of the reason we've partnered with Microsoft is that they're willing to take that bet."

No release date has been confirmed for the game yet, other than the fact that it won't be here in time for Christmas 2011.

With The Walking Dead getting stellar TV ratings last fall, zombies continue to be all the rage. The latest media offering to feature the undead apocalypse was announced today in the form of an upcoming exclusive title for Xbox Live. Code-named "Class3," the title will be an "open-world zombie-survival game" and will support one to two players for online or split-screen co-op.

The zombie apocalypse is headed to Xbox Live.

No release window was given for Class3, which is in development at Seattle-area studio Undead Labs. The third-person title will have shooting and driving elements, as well as melee combat and a high gore content. Besides fighting off the undead hordes, gameplay will consist of fortifying settlements, rescuing other survivors, and going on raids for supplies.

Published by Microsoft Game Studios, Class3 will be the first step in developing a full-fledged massively multiplayer game for the Xbox 360, code-named "Class4." In a Q&A on the Undead Labs website, studio founder Jeff Strain, formerly of NCsoft, described how Class3's development will lead to that of Class4. He said that the latter will build on the former's framework and gameplay, leading to a title that "allows thousands of gamers to play together in a persistent online world that evolves and reacts over time to player actions."

To date, the Xbox 360 massively multiplayer game fraternity has been a very exclusive club. So far, only Final Fantasy XI has made it to the platform, with Marvel Universe Online and Champions Online being canceled for the console and Star Trek Onlineand Age of Conan languishing in development purgatory.