Greetings,
I am a huge fan of Xamarin and especially of the ability to leverage Xamarin Forms to create a "shared" UI for all of my common elements. That said, I find it both frustrating and disappointing that there is still no usable Designer for this "shared" XAML. Now that Xamarin Forms is starting fill out, I would think it should be possible to leverage at least the Visual Studio extensiblity framework for the design and allow for at least a "view only" preview of the XAML.