Viable Web Services

With the context of my previous post regarding "fast" SOA, I'd like to mention an approach focused on web services, suggested by Arjen Poutsma. As you may experience, strict validation of messages incoming to your web service sucks. It is time consuming, complicates service versioning and refuses messages which holds all the necessary information and thus can be processed. Remind the Jon Postel's Law, don't be strict.
The next step? Don't struggle with object-to-XML mapping, use XPath for handling the data. I don't know about any OXM solution, which is robust enough, can handle all the pecularities of XML Schema, passes the "XML schema <-> objects" round-trip test etc. If you consider XPath as slow, optimize it eg. by SXC.
To be specific enough about this approach, I has to mention Spring Web Services (into which Arjen is involved as well). You can use them tradionally with ORM like JAXB, XMLBeans etc. or use JDOM and XPath, like in this tutorial. It seems to me much more viable solution.