Microsoft plans to share more about the Windows 8 app store at a two-hour preview event in San Francisco on December 6.

Microsoft has invited select developers and local press to hear more details on the Windows Store. The spokesperson declined to share more details prior to the event.

December 6 also happens to be the day when Microsoft will be rolling out its new Xbox 360 dashboard. Testers who've been working with a test version of the dashboard (under non-disclosure-agreement terms) have mentioned in passing new app store functionality in the dashboard. Facebook, Hulu, Netflix and Twitter are listed under apps in the preview, testers have said.

Microsoft officials shared some high-level details about the Windows Store at the Build conference in September, even though the Store isn't operational in the Windows 8 Developer Preview build. They said all Metro-style apps would be available only via the Windows Store. Metro apps will be protected by an account-based (not a machine based) licensing model that is limited to a set number of machines (5). Users will be able to access app trials, buy/download Metro-style apps, license them, have them serviced through the Store.

Desktop (non-Metro-style) apps will be able to be promoted in the Windows Store if they meet Microsoft's Desktop App certification requirements, and will be discoverable via the Windows 8 store. Windows 8 Desktop Apps will be neither licenesable nor downloadable (i.e., able to take advantage of the Windows 8 “fulfillment service”) from the Store. Instead, Microsoft will only provide a link to the Windows Store for Desktop Apps on Windows 8 on x86/x64 and ARM.

Will there be any overlap between the Xbox 360 dashboard apps section and the Windows Store in Windows 8? Hopefully we'll hear more next week...

In other Windows 8-related news, there are reports (from WinUnleaked.tk, which I saw via WinRumors.com) that Microsoft has begun using the name "ReFS" to refer to the Protogon file system that was spotted by hackers in early leaked Windows 8 builds. There was speculation earlier this year that Protogon might be a new file system, possibly supplementing or replacing the current NTFS in Windows. Since that time, Windows 8 enthusiasts have moved on to thinking that Protogon is more of a content/metadata file system.

And TheNextWeb is reporting that the Windows 8 beta won't be out until "late February" 2012. I have been hearing it would be a post-Consumer Electronics Show thing, but have not heard any further date information beyond that....