For anyone else reading this article. Microsoft have released Visual Studio 2013 Community Edition which is free and works well with Visual Micro.
The older free "Express" version of Visual Studio did not work because at the time of its release Microsoft prevented plugins from working with it.
So Visual Studio 2013 Community is a good solution or Atmel Studio which is slightly better for pure Arduino development and based on Visual Studio.
Please see more at http://www.visualmicro.com