XMLPersistence 1.1 released
1.1 version supports XPath 2.0 XQuery 1.0, and XUpdate. Many bugs have been fixed (especially in namespace handling). This release include HSQLDB in memory config file to run the XML Persistence in standalone mode.
This version relies on Saxon 7.8 and Lexus XMLDB:XUpdate 0.3 to provide XPath/XQuery/XUpdate features.

BTW it also support ISORelax DOM schema validation (check test files).

You need to download Hibernate 2.1.1 and link the lib to the application to be able to run the persistence stuff.

You can download 1.1 full release right now.
Or get the last source from CVS.