Paul captured my sentiment/intent.

I can write efficient relaiable apps in several languages. I'm especially good at real-time back-end processing apps and diagnostic tool. I know MFC very well. But I know next to nothing about the .Net platform.

I recently started a new job and will be converting an MFC app to C# with Windows Forms. I expect in a year or so to be very good with C#.

If you have a solid grasp of programming theory, switching between languages and tools is just a matter of learning the syntax and the Object Model (and coding conventions for that language).