Yesterday I installed JBoss 4.2.3 and deployed Geoserver 1.7.6 to it and installed the OracleNG plugin. Unfortunately, after setting up the Oracle datastore and some features, inserting via WFS-T still resulted in an empty geometry in the database.
SVN access to the OpenLayers trunk gives an error at the moment, so I guess I’ll have to do some further testing with the 2.0RC of Geoserver.