Besides the "Mono wave" on Gnome seems gone. Now there are some guys pushing Vala, and it reminds me the time when Mono was the future of Gnome.
https://live.gnome.org/Vala
Several Gnome applications have been rewritten in Vala and, having contributed a patch to Déjà Dup, I find it's a language easy to hack coming from a C/Java/C# background.
I always found interesting that Mono could have been a good thing for Gnome and because of the Microsoft influence in the language (or .NET platform, I'm no expert) it never happened.
EDIT: ate a word