According to Microsoft, DirectX is the unified graphics foundation for the Windows, Xbox, and Windows Phone platforms. Microsoft recently revealed that the company would be retiring XNA, and focusing on DirectX.
"The XNA/DirectX expertise was created to recognize community leaders who focused on XNA Game Studio and/or DirectX development. Presently the XNA Game Studio is not in active development and DirectX is no longer evolving as a technology. Given the status within each technology, further value and engagement cannot be offered to the MVP community. As a result, effective April 1, 2014 XNA/DirectX will be fully retired from the MVP Award Program," the email announcement from Microsoft stated. Microsoft apparently made a mistake in the announcement in terms of the wording used to describe DirectX's status. When asked again, Microsoft reiterated: "Microsoft has people across multiple divisions working on DirectX technologies. We are actively innovating and evolving DirectX and it will continue to be the world’s leading low-level high performance interface for gaming and graphics across Microsoft platforms." So there you go. DirectX is not going anywhere and is a crucial part of the company's major platforms. Also, keep in mind that Direct3D is a part of Windows 8's core and is no longer considered a "technology" just like GDI or Winsock.
XNA, for those that didn't know, was Microsoft's .NET compliment of DirectX, announced back in 2004. Microsoft eventually released XNA Game Studio for developers to create games for Windows. Microsoft eventually revealed that Windows 8 would not support XNA in a sense, due to XNA not being able to be used to create Metro apps. Now, Microsoft is completely halting development of the XNA Game Studio, however, will still be offering support for developing games in Xbox, Windows, and Windows Phone.