This is no real description of a technology. It is more a statement of the development team. All new configuration files will be in XML.
The idea of all the XML files is the possibility to edit the configuration with texteditors and XML editors. So it is possible to develop a graphical interface for the configuration of OpenCA. The real important statement is the DTD. Today there is DTD but every XML file must contain <openca> as root element. The element below the root element must describe the type of the configuration (e.g. <token_config>). This makes later integrations of different configfiles really easy.
Today we have no DTD but it MUST be written before version 1.0.