I am considering doing the NMF port to the K60.
I think the framework has a valid place in embedded development. I've developed in assembly, C, C++ and C#. Each level upward offers greater abstraction, easier-to-use libraries/classes, and increased error handling. In other words, I can do something in C# faster, and more robustly, than I can in C.
And consider how it can benefit smaller companies with 1-10 programmers. One person can develop the embedded code for some PC-connected embedded device and also develop the PC GUI to interface with it. He/she uses the same Visual Studio for both. Many programmers that want to expand their usefulness and skills would love to add embedded work to their resume.
And consider that C# Express is a free tool that does absolutely everything you need.