I just uploaded new source files for the JavaEOXMLSupport framework on the woxmlsupport project on Sourceforge.net.
It's got support for accessing and editing XML data in documents via KeyValueCoding (although I've found a bug - it doesn't like creating elements that don't exist, so it's literally an editor at the moment).
I also uploaded source for a test application (xmldbTester), which uses both JavaEOXMLSupport and JavaXStreamDBAdaptor frameworks. You'll need your own XStreamDB database at the moment (free for educational users), but it works fine.