This is a feverish and interesting debate. I have some experience of working with uploading IMS packages and SCORM compliance using another VLE. Despite that experience, I still find that there are features of these standards that elude me. However, I do want to join this discussion. My experience suggests that there is a lot of hype about the benefits, which are really some way off (not an unusual circumstance with IT).
From a learning object management perspective when there is a large volume of resources, the metadata is already a small benefit. My academic colleagues are typically very time pressured and properly catalogued resources can help in a resources search. If the key words and description are well chosen (and that depends on the person doing the packaging, as Jenny has already said), the cataloguing is easier. A hope would be for some emergence of real standards in this area, but I suspect the various projects that have been started for this still have a long way to go and that some complexity will always need to be managed. This is also about reuse or repurposing being able to discover that there are elements to be recombined or amended in the first place.
In addition, my experience is that compliance is elusive, even when claimed. Manifest files for most packages that I have dealt with have been faulty. This weakens another small benefit, which is the speed of upload or deployment. I would like to be able to upload a new version of an object quickly (needed when there are errors or necessary updates in the learning material!), but that isnt going to happen unless the manifest is correct in the first place.
Writing assessment results back to Moodle would be beneficial, but with small chunks of learning can introduce unnecessary complexity for the teacher when tracking (assessment types need to be distinguished, self-assessment, formative, summative). Another SCORM feature, bookmarks, could be helpful to learners, but I havent seen it work in an externally produced package, yet.
A point on which I need some clarification is: what will an unpacking create in Moodle? At what level of deployment: the Moodle resource level, topic level, course level? I have seen many very small chunks of learning object how can these packages be managed, so that they dont unbalance the system? Perhaps Jenny has already addressed this, but I havent been able to view her examples.
So, I do want the features that Martin has summarised. I believe that some degree of compliance is necessary for the continued success of Moodle. However, I dont expect this pathway to be smooth, nor do I anticipate the hype to be fulfilled for some years (if ever).