On his blog, Peter Leithart posted an article from Biblical Horizons (not available on the Biblical Horizons website) on what is going on in Jude 9. I very much enjoyed it, and he did a great job of tying Jude 9 into the context of the rest of scripture.

From the post…
Jude 9 raises several difficulties (though not insuperable difficulties) for conservative commentators. The event that Jude recounts does not seem to be drawn from the Old Testament, and most scholars claim, based on statements of Clement of Alexandria and Origen, that Jude borrowed this story from the Assumption of Moses, an apocryphal work. If true, this raises the question of the status of apocryphal literature in general. We can, of course, defend the inerrancy of the canonical Scriptures even if this is the case. The Spirit, after all, might have led Jude to refer to this story, even though it came from a noncanonical book. But questions continue to nag at us. Is the story historical? Or, does Jude quote from a popular legend simply to support his theological point?

Link: http://www.leithart.com/2008/04/07/michaels-dispute/