True XNA is dead essentially.. Monogame is open sourced XNA and far from dead.. literally your xna 3 or 4 game runs with almost no changes in monogame.. Namespaces etc were all preserved.. =D its in active development and has solutions to build for iOS, Android, Mac OS X, Linux, Windows 8 Store Apps, Windows Phone 8, Windows desktop apps, OUYA and last I heard playstation mobile dev was in the works.. I've actually published a couple games on the windows 8 store with monogame.. and working on several more currently.. I plan to port them to iOS, droid, linux and mac as well, just have to come up with the money for the xamarin tools to do so..
Ive tried unity.. construct.. game maker studio.. game salad.. and I keep coming back to the fact that Im a programmer.. lol those gui's and crud just throw me off my game.. I do think however I might use Unity to 'draw' up some 3d scenes and then use those as 2d images in a couple of my projects.. someday.. someday maybe I'll start learning 3d.. and just maybe... find unity useful.. ;)