If you want to read an account that explains why adaptive learning (among other things) is a difficult problem that is not likely to be solved by IMS standards (or any other standards, for that matter), then check out this PowerPoint presentation:
Deep stuff here. Some of the XML implementation stuff in Section 5 gets a bit over my head, but the philosophical underpinnings are clearly right on, IMHO. Really, really good stuff.
BTW, here's a much less profound but still interesting piece on Simple Seqencing, how it affects SCORM, and what it's limitations are: