XStream 1.2.2 is released with
JettisonMappedXmlDriver used for serialization and deserialization from JSON. It is the driver first presented in Java and JSON post. All modifications are submitted to Jettison and XStream projects respectfully and documented in an appropriate tutorial (http://xstream.codehaus.org/json-tutorial.html). From now on, XStream has a full support for JSON serialization. Enjoy.