Microsoft this week responded to persistent rumors about an upcoming new Zune digital media device called the Zune HD. It's real, the company says, and will ship in the US this fall. But I can be a bit more specific: According to my sources, Zune HD will ship on September 5, 2009.

"This is the next step in our strategy to broaden Zune as an entertainment service for Microsoft," a posting on Microsoft's official Zune Insider blog reads. "We are really excited to bring the new Zune to market later this year, and ... we will be coming to Xbox, taking over the existing video marketplace and bringing a rich new experience with new features."

The Zune HD is positioned squarely against Apple's popular iPod touch, Microsoft says. The company has revealed the following details about the device: