An updated version of XML::STX has been uploaded to CPAN. This version is supposed to be the last one in the current development branch; the processor is going to be rewritten nearly from the scratch now.
A significantly updated working draft of STX 1.0 specification is available. The changes move STX closer to XPath2. The STX data model is derived from the XQuery/XPath2 data model, and STXPath is derived from XPath2 now.