The most interesting part of this leak is that the copyright date clearly shows the year 2012. Rumors have claimed Windows 8 will be released on January 7, 2013, but we have argued against them. We've known for a while that Microsoft is targeting 2012 for the release of Windows 8, though of course, nothing is set in stone.
The build in question is from Milestone 1, which means it is outdated if we are to believe the rumors that Milestone 2 has already been compiled. This happens often: leakers can't always get their hands on the latest builds.
As a new Microsoft operating system takes shapes, the Windows enthusiast community comes together to share and discuss new builds. We're looking forward to the upcoming leaks. Are you?