Nothing new here
This has been around for many years. It may have gone away and come back, but I don't think so.
I worked at a place that signed up to an early version of the 'shared source' program in the late 1980s, and I don't think it's changed much since then.
http://www.microsoft.com/en-us/sharedsource/enterprise-source-licensing-program.aspx
As you can probably guess, there is a serious NDA involved.
:-)