The XML IO System is part of jME 2.0! The new Blender exporter for jME 2.0 xml is in the download area: http://jmexml.googlecode.com/files/jmeXMLExport_V2.py This is all you need if you are using jME 2!

jmexml is a XML serialization system for the jMonkeyEngine high speed java scenegraph engine, Version 1 (jME 1). It is based on jME's standardized serialization system.

This project is also a place to stay for jME's abandoned "old style" XML serialization format. While the xml and underlying binary serialization are deprecated since jME 0.11, they are still usable with jME 1.0, but no longer part of jME's source tree. You can download the old (jME 0.11) xml exporter here: http://jmexml.googlecode.com/files/jmeXMLExport.py

The exporter for jME 1.0 xml is here: http://jmexml.googlecode.com/svn-history/r9/trunk/jmeXMLExport_V2.py