Dave, I'm certainly the last person to be taken as the authority on implementation. However, FWIW, SCORM and Simple Sequencing envision courses as client-side packages that are independent of the back end. Typically (though not always), the course content would be developed entirely in client-side technologies independent of an LMS and then imported into the system. The LMS (in theory, though often not in practice yet) would gather the content structure from the course's SCORM manifest (which is an XML document) and generate the navigation. So, since externally developed course packages that use SCORM (which, I understand, will eventually interoperate with curriculum) will need to deal with XML for navigation generation anyway, it might be a good idea to look at the implementation from this perspective.