Microsoft's XNA may be dead, but XNA development lives on with MonoGame!
(
http://gamasutra.com/view/feature/192209/from_xna_to_monogame.php)
Also, there are several games on Xbox Live Indie Games made in IG Maker. Some notable ones include Space Milkman, Tempura of the Dead, and Nyan-Tech.
Also, there
are still games being released on XBIG (as of this post, the most recent was released on 20 April 2015), so it's not
completely dead.
I've actually been considering starting a thread to keep track of released games made in IGM, I'm just not sure which board it belongs on...