Some very exciting things there for Mono.

* SGen is now default GC

* There's an API to ask GC not to run during critical sections

* Much faster build times

* F#, RX now bundled with Mono

* Xamarin.Mobile, Xamarin.Auth, Xamarin.Social open sourced

* Zynga created PlayScript, a superset of ActionScript that runs on Mono (everywhere Mono runs including on iOS/Android), can be mixed with C#

* A new C++ binding technology called CppSharp using clang that calls C++ directly with no glue

* You can inline ASM in C# code (insane right?)