Okay, this is awesome: http://blog.xamarin.com/2012/05/01/android-in-c-sharp/

While I'm suspicious of all JIT-compiled languages, C# has always had a much better IL than java, even since version 1.0, making it easy to win benchmarks like this (and it translates to the real world too). I don't honestly expect Google to start switching en masse from Java to C# - if only! - but it's an amazing experiment and I love some of their reusable optimizations (like writing a C# layer that interfaces directly to the native rendering libraries, bypassing the slow Java stuff, even in your C# apps on normal Android).

For anybody familiar with VM design and optimization, performance discussions about .NET vs. Java go something like this:

.NET guy: Value types.

Java guy: Okay, you win.