>I'm not at all qualified to answer the question posed but do feel that I've read enough to be able to say that .NET is a far far bigger investment in time, learning, practise, etc. than just switching programming languages.

I'm of the opinion that the languages have nothing to do with it. (Disclaimer: I'm also of the opinion that all languages are the same, just tell me what the dialect is.) Learning the class hierarchy, and which class most efficiently does the job, is the hurdle. The best analogy I can come up with is learning the Win32 API. Sure, you may know C++, but that doesn't do you a lot of good when it comes time to shut down a process if you don't know the API.