The best feature of Windows Phone 7, Microsoft’s mobile operating system, is one that will differentiate it from the rest of the smartphone platforms on the market: Xbox Live integration. This feature will help players carry their online persona into the real world, said Matt Thompson, general manager of developer and platform evangelism for Microsoft. Thompson made the comments at the GigaOm Mobilize conference in San Francisco today.

Tthe rest of the smartphone market has made a push into gaming, including the iPhone with Game Center, but Thompson expects  Xbox Live integration to be the “hook” that helps sell Windows Phone 7 devices and unseats Apple’s iPhone iOS operating system, BlackBerry OS and Android as the dominant mobile platform.

“Clearly the phone is you, so the most unique thing we’re trying to do is bring XBox Live so you can carry the online ‘you’ into the rest of the world,” Thompson said.

In addition to bringing social games like Zynga’s Farmville to the Windows Phone, Microsoft is sparing no expense in helping develop traditional 2D and 3D games for the platform that would mimic the XBox Live experience on a console, Thompson said.

Games for Windows Phone 7, including the Babylon Twins app Thompson demoed on stage, are written on XNA, a different architecture than Microsoft’s Silverlight platform, which was used for the rest of the apps. The marketplace for Windows Phone 7 apps would be open in the next couple of weeks, not months, he said. Microsoft announced earlier that it would have more than 60 Xbox Live games available for the launch of Windows Phone 7.