It has still to be shown that all the wished functionality can be easily implemented. The problems still remaining are more precisely the following:
The format of concept maps for printing. Optimally, they should be exported to EPS from Conzilla, using the Java Printing API, for example, to allow highest possible resolution (no visible pixels in fonts etc.). That this works is displayed by this example image:
Example 19-1. Figure example

The exact meaning of links in the document in a Conzilla environment: a link to the corresponding concept, a link to the corresponding content, or in some way both? Another problem is the inclusion of suitable JavaScript code to talk to Conzilla. See Chapter 17, External Cooperation.
The meaning of a concept map in the online version. It should probaby be used to start the Conzilla browser on the map, either inline or via a link. As content in a Conzilla environment, they would be importable (and therefore surfable) into the Conzilla browser. the corresponding JavaScript code remains to be written.