The great thing about .net is there are different options to choose from. This is why I am always confused with "VB developers" or “C# developers”. To me you should strive to be a .net developer, so maybe if you are a specific "developer" you should be worried.
Wasn't the entire appeal of .NET the ability to work in the language (and by extension, the style) of your choice? Whichever one makes you most productive...
To force people to adopt both languages, or to force a choice between them based on the technologies you wish to work with is counter to the entire concept of .NET.