XML Mapping Task Pane

This was added in 2013
For 2010 and 2007 this can be downloaded from CodePlex as a separate add-in.
This add-in adds a Mapping Group to the Developer tab.
The task pane displays all the XML Parts in the active document.

Functionality
Add xml parts from an existing XML file or by directly entering its content
View a list of attached xml parts
View the contents of each part as a tree
Drag and drop xml nodes into the document
Map existing content controls to specific xml nodes