is it time for .NET developers to flee the .NET sinking ship?
Regardless of whether .NET is declining or not, I think that no developer should limit herself to just .NET (or any other technology for that matter). Don't "flee", but yes, definitely be curious about other technology.
Also, keep in mind that there's so much more to programming than .NET/Java-EE/Obj-C-Cocoa/C++. I'm mostly thinking of dynamic languages (
a la Python, Ruby, Perl, Groovy, Lua) or functional languages (Lisp, Clojure, Haskell). If you're interested in these languages, it's never too late to adopt them. You'll find plenty of people here on LebGeeks familiar with them and willing to help you.
Finally, note that .NET is transcending the limits of just Microsoft. There are alternate implementation running on so many different systems.
Xamarin (a child of Novell) already has a powerful implementation called
Mono (running on Windows, Mac and Linux) and they have some prototypes to
run C# on Android.
Note there's a lot of sensationalism in the ArsTechnica article (surprise, surprise!). Don't go claiming that Android is dropping Java for C# just yet. The article is idiotic, I already gave my opinion why.