It's also important to note that "XNA" isn't a language, it's an API.
C# is the language usually used with XNA, and C# support hasn't ended. Just because one API of your language has been feature-frozen, that doesn't mean you need to abandon the entire language. You could switch to the open-source replacement for XNA, called MonoGame, or you could switch to something like Unity Engine, which is heavily used and heavily supported, and continues to be developed.
As for as developing your skills go, it'll be more beneficial to use the tools available to you to complete projects, than to switch languages whenever it seems like the language is being ill-supported. Until two years ago, it seemed like Microsoft had abandoned C++ to support C#. Now it seems (at the surface level) like Microsoft has abandoned C# to support C++. Chances are they'll release XNA 2.0 shortly after the XBox One launches.
Ironically, I had a similar 'crisis of faith' in C++ about two years ago, as all the programming news I was hearing was shouting "C#, C#, C#!".
A good tool is a good tool, and it's sometimes confusing when the winds of media hype for different technologies blows counter to the direction you were heading in.
I ended up deciding to stick with my current language, because I realized it's more important to actually finish a project, then it is to make sure that that project uses Company X's favorite language of the week. C# isn't dead, even if XNA has been sunsetted. XNA != C#