The Central Plaza in Sony's PlayStation Home virtual world.

Sony will launch its PlayStation Home as a public beta Thursday, throwing open the doors to a virtual world that the company has been developing now for years.

But don't look for the Xbox 360 to follow the PlayStation 3's lead with a virtual world of its own. Although Sony would obviously disagree, a Microsoft representative contended today that virtual words as a phenomenon are on the decline.

Like Microsoft's revamped Xbox Live service, the PlayStation Home will let gamers create custom avatars to represent themselves.

Unlike the Xbox experience, avatars in PlayStation Home will be able to run free in an open digital environment. They'll interact with other members of the community, explore public spaces and play mini-games, among many other activities.

It's an engrossing experience, with lots of interesting areas to check out, based on a demonstration I was given by Sony a few weeks ago in Seattle. It will be fascinating to see what happens when the broader PS3 community is given access Thursday.

PlayStation Home is also an important part of Sony's broader console strategy, giving game developers and publishers the ability to establish their own dedicated spaces within the virtual world.

Microsoft and Sony are fierce rivals in the console market, currently competing for second place behind Nintendo's market-leading Wii console. So why won't Microsoft be following Sony with an Xbox virtual world?

"A couple years ago, when they announced Home ... there was kind of a virtual-world boom at the time, and people were fairly excited about this," said Aaron Greenberg, Xbox 360 director of product management. "But it feels like now, a couple years later, people have kind of moved beyond that, and they've done the virtual world thing, and they're ready for something else."

The avatars in the New Xbox Experience are primarily used as part of the on-screen menus, but they can also appear as characters in games.

In related news, Microsoft this afternoon released the first batch of statistics about the New Xbox Experience, following its rollout last month. Among other stats, the company says movie downloads were up 49 percent and TV downloads 30 percent in the week after the launch, and Xbox Live Arcade sales nearly tripled in the same time period.