The majority of Android developers use Java to create their apps. While Java isn't the hardest programming language to learn, it's always best to get as many people developing as possible.... not that Android is hurting in that respect. Even so, a new way to create apps using Microsoft's familiar C# language is now available, by way of TallApplications BV's Dot42 - a tool that aims to accomplish this task without requiring something like mono.
The gist is simple: it's a compiler that will allow you to code apps in Visual Studio. You can use existing Android API libraries. There's even limited support for editing String and Menu resources in WYSIWIG.