Building an Office Add-in without the pain of VSTO or COM

Use your existing C# and XAML skills to build Office Add-ins using WPF. Admittedly uses a 3rd-party tool, but worth the price of admission to avoid VSTO and COM. Will show how to wire up to use a standard WPF UserControl, and tricks to get drag-and-drop working as well. Am currently using this in a production application, so open to any questions/discussion.