To put it in Microsofts' own words :

"Be at the forefront of innovation. The Kinect for Windows platform transforms the way people interact with technology. Help unlock the possibilities.

The release of the Kinect for Windows sensor and software development kit (SDK) for commercial applications opens up the limitless possibilities offered by Kinect technology. Together, the hardware and software offer a superior development platform for Windows and a higher quality, better performing experience for end users.

To further incite innovation, the Kinect for Windows hardware will be available through a variety of resellers and distributors in the United States, Australia, Canada, France, Germany, Ireland, Italy, Japan, Mexico, New Zealand, Spain"

The Kinect for Windows SDK includes the following:

• Drivers, for using Kinect sensor devices on a computer running Windows 7, Windows Embedded Standard 7, and Windows 8 Developer Preview (desktop applications only)
• Application programming interfaces (APIs) and device interfaces, along with technical documentation
• Source code samples

Download below