Sven, I'd suggest you open up, and avoid what I call the Microsoft ghetto. I'm not talking about server-side technologies here, use ASP.NET AND C# as much as you want (you're only hurting youreself ).
I'm talking about the disconnect Microsoft developers have with current client-side libraries/frameworks and JS tools in general. I think they still need the nod from mother Microsoft in order to use anything, and god forbid they use anything from arch-rival goog.
I think things are so bad that a special web conference was created just for them (!?).
For me it's plain that a revolution is unfolding before our eyes. One that's bigger the last revolution. The last one being the one that standardized the OS and its API, (settling on POSIX of course).
If one belittles the web stack and open source, he/she just missed the TWO most important things that came from computing recently.