Today there was a release of a draft of the UBL draft specifications. I pulled them down and there's legalisms, and definitions, and schemas, and UML, but not one single example of a UBL message.... Argh!!!!!
I can't emphasize how important it is in technical specifications, particularly in XML-related ones, to have lots of examples. This is the lesson of the Web; when you have something that's useful, and people can figure it out by doing "View Source", they will, and they'll start doing it, and the technology will spread virally.