A well-connected but regularly erroneous publication is reporting that Microsoft is developing Windows Blue as a project that will merge desktop Windows with Windows Phone.
So far so good. Windows 8 and Windows Phone 8 already share lots of bits and pieces. The kernel is the same across both platforms, big chunks of code like Direct3D and .NET are identical, and there are some pieces of the new WinRT API also common to both.
There's also been a leaked, new Windows build that adds onto Windows 8 but makes multitasking more versatile, and makes the touch-first, Metro environment more expansive. Later builds contain "Windows 8.1" branding, which would make sense for a minor release that's generally expected to ship late this year.
Is Microsoft integrating Windows Phone and Windows? You’d hope so | Ars Technica