Great to see Microsoft making progress with Roslyn and the .NET reference source - September 2012 was a long time ago. Lets hope the up and coming previews will happen in the near future so we can begin to experience and understand the advantages of Roslyn in application development.
Last thought: “dogfooding” is critical in my view to development of software. Silo mentality and throwing over the wall (e.g. to support, QA, clients) without dogfooding is just wrong