Xamarin has just announced that they got the Java part of Android ported to C# via machine translation. The resulting OS, called XobotOS, is available on Github. They claim some serious performance gains over Dalvik. For them, this is an experiment that they are not planning to focus on, but they will be using some of the technologies in Mono for Android
http://developers.slashdot.org/story...id-ported-to-c