Version 3.4.1 of WPF Diagram control contains several customer-requested features and bug-fixes:

ShapeListBox control
The ShapeListBox control displays a list of Shape icons along with their DisplayName. It lets users drag-and-drop a Shape to the diagram's canvas to create a new ShapeNode. Set the ItemsSource property to an array or collection of shapes that should be rendered inside the control. For example, setting the Shape.Shapes list as ItemsSource will show all pre-defined Shapes. You can customize the shape appearance by setting ShapeBrush and ShapeSize properties.

Miscellaneous
~ a NodeRenderer added to custom node templates will now repaint automatically when any dependency property of the node changes.
~ set Selection.FreeFormMode to enable free-form lasso mode that lets users draw irregular outline to select items inside.
~ HeadStrokeDashStyle property added to DiagramLink lets you set the dash style of arrowhead outlines independently from link segments' one.
~ fixed orientation change gesture for cascading links with AllowSplitSegments enabled.
~ PdfExporter now creates page hyperlinks if DiagramItem.HyperLink is set to a value in "page://{number}" format, e.g. set "page://1" to open the second PDF page when the item is clicked.
~ the Visio Stencils import API provides access to BeginArrow and EndArrow values.
~ the Visio Stencils import API provides access to Connection elements defined for a shape.
~ fixed bug in ResizeToFitText(KeepRatio) method with long words in the text.

If anyone is interested in trying the beta version, please download this archive containing updated assembly files:
https://mindfusion.eu/_beta/wpfdiag341.zip

Any comments, questions and general feedback are welcome.