For version 1.2 we have enhanced the State Chart sample to support user dragging (moving) of link labels.
On the left is the start diagram; on the right the diagram after dragging the link’s label towards the right.
The label remembers its position relative to the center of the link, so that if one moves a node, the label is repositioned appropriately along the new link route:
We have also enhanced several samples (including State Chart) to save and load link routes to/from XML.