They've admitted that progress has slowed but have also explained why and it's got nothing to do with enterprise customers.

The reason is that they're rewriting the C# compiler using, er, C#. It's as part of an initiative called "Roslyn" that aims to make the compiler a pluggable component with a public API for the compilation AST.

They did a blog post recently explaining that whilst this work is ongoing they are trying not to change the C# language too much to aid them with testing and verification. But that once Roslyn is released they will start a fresh wave of language enhancements for C#. I think we all have some ideas on what those will be to start off with... proper tuples support, and probably some form of pattern matching.