Hi Bitli,
The next version of PixInsight will include two new core JavaScript objects, namely XMLStreamReader and XMLStreamWriter. These objects will implement sequential reading and generation of XML code through an easy-to-use high-level interface.
XMLStreamReader and XMLStreamWriter, however, don't load or represent an XML document as a tree of nodes, in the fashion of the XPath specification. They will provide, however, the necessary functionality to decode common data types as numbers (both floating point and integer), dates and Booleans from XML attributes.