Over at patheos, there's an ongoing debate between BYU historian William Hamblin and church historian Philip Jenkins. I've only read one of Jenkins' posts. Jenkins makes some good points.
i) Problem is, Jenkins is resorting arguments which, without further qualification, could be turned back on the Bible. Christian apologists should avoid using arguments to debunk the Mormon "scriptures" which could be used to debunk the Bible. Likewise, they should avoid backing themselves into a corner where they appear to indulge in special pleading. They need to anticipate objections, get ahead of potential objections, and fine-tune their arguments in a way that avoids invidious comparisons.
ii) The Humean criterion that extraordinary claims demand extraordinary evidence is hopelessly ambiguous and ill-conceived.
iii) Where should we assign the burden of proof? Does the onus lie on the Christian apologist to disprove the Mormon "scriptures"? Of does it lie on the Mormon to prove his "scriptures."
Is there a standing presumption that Joseph Smith was a genuine prophet, which a Christian apologist must overcome? Surely not. What reason is there to take him seriously in the first place?
iv) Apropos (iii), according to Joseph Smith:
9 My mind at times was greatly excited, the cry and tumult were so great and incessant. The Presbyterians were most decided against the Baptists and Methodists, and used all the powers of both reason and sophistry to prove their errors, or, at least, to make the people think they were in error. On the other hand, the Baptists and Methodists in their turn were equally zealous in endeavoring to establish their own tenets and disprove all others.
10 In the midst of this war of words and tumult of opinions, I often said to myself: What is to be done? Who of all these parties are right; or, are they all wrong together? If any one of them be right, which is it, and how shall I know it?
19 I was answered that I must join none of them, for they were all wrong; and the Personage who addressed me said that all their creeds were an abomination in his sight; that those professors were all corrupt; that: “they draw near to me with their lips, but their hearts are far from me, they teach for doctrines the commandments of men, having a form of godliness, but they deny the power thereof.”
That invidious contrast was easier to make at the time, before the Mormonism began to develop its own track record. But consider all the factions: the LDS v. the RLDS. The breakaway polygamist sects. Some BYU professors v. the Mormon hierarchy. Is Harry Reid a paragon of virtue? What about Mormon serial killers like Glenn Helzer, Ted Bundy, and Arthur Gary Bishop?
v) Apropos (iv), this isn't just a debate between Mormons and outsiders. You have in-house debates. For instance:
It has been suggested by some, even among members of the Church, that the Book of Mormon is a nineteenth-century book, either written by Joseph Smith or received through revelation, and that it has no basis in any real, ancient, historical events. Some who hold this point of view hasten to add that though the book is not historical, it is nonetheless “the word of God,” “inspired,” and/or “true.” This appears to mean that it qualifies as such while the events that it describes never took place. A variation on the suggestion is that it comes from God or is otherwise “true” but that it does not matter if the events that are described in it ever happened.
Using the parables-are-true-but-not-historical model, friendly critics of the Book of Mormon’s historicity argue that it does not matter whether the events and individuals in the Book of Mormon are historical, because the aims of the book are achieved independently of its historicity. In other words, like parables or other good works of literature, the Book of Mormon can teach its true principles even if the events in it never happened. Thus it can still be the word of God.
 According to Anthony A. Hutchinson, “Members of The Church of Jesus Christ of Latter-day Saints should confess in faith that the Book of Mormon is the word of God but also abandon claims that it is a historical record of the ancient peoples of the Americas. We should accept that it is a work of scripture inspired by God . . . but one that has as its human author Joseph Smith, Jr.” “The Word of God is Enough: The Book of Mormon as Nineteenth-Century Scripture,” New Approaches to the Book of Mormon: Explorations in Critical Methodology, ed. Brent Lee Metcalfe (Salt Lake City: Signature Books, 1993), 1. A similar notion that is even more intellectually inconsistent is found in Blake T. Ostler, “The Book of Mormon as a Modern Expansion of an Ancient Source,” Dialogue: A Journal of Mormon Thought 20, no. 1 (spring 1987), 66–123.
 According to Hutchinson, “Ultimately whether the Book of Mormon is ancient really does not matter.” Hutchinson, 16. According to Mark D. Thomas, “In the final analysis the book’s authority cannot depend on its age. If the Book of Mormon’s message is profound, that alone should be sufficient reason for serious analysis and dialogue.” “A Rhetorical Approach to the Book of Mormon: Rediscovering Nephite Sacramental Language,” Metcalfe, 53.
Brigham Young, for instance, recalled some of those (clearly beyond the better-known “official” witnesses of the Book of Mormon) “who handled the plates and conversed with the angels of God, [but] were afterwards left to doubt and to disbelieve that they had ever seen an angel.” One of the early members of the Quorum of the Twelve, whom President Young described as “a young man full of faith and good works,” “prayed, and the vision of his mind was opened, and the angel of God came and laid the plates before him, and he saw and handled them, and saw the angel, and conversed with him as he would with one of his friends; but after all this, he was left to doubt, and plunged into apostacy, and has continued to contend against this work. There are hundreds in a similar condition.” Journal of Discourses (London: Latter-day Saints’ Book Depot, 1854–86), 7:164.
vi) There needs to be more discussion regarding when the argument from silence is weak or strong. There are some parallels here concerning the minimalist/maximalist debate in biblical archeology.
For instance, critics like Thomas Thompson, Hector Avalos, Peter Enns and Israel Finkelstein appeal to archeology to deny the historicity of the Exodus and Conquest. So we need to discuss when the argument from silence is legitimate or illegitimate.
Scholars like Kenneth Kitchen (On the Reliability of the Old Testament) and Duane Garrett (commentary on Exodus) do a nice job of explaining why we wouldn't expect direct corroborative evidence for the Exodus to survive. For instance, Hebrew slaves lived in mudbrick huts that wouldn't survive in the Nile Delta, which as a river basin and flood plain. By the same token, papyri wouldn't survive under those conditions. You have monumental inscriptions on Pharaonic tombs, but that's royal propaganda.
Likewise, Douglas Stuart (commentary on Exodus) estimates the number of Israelites in the wilderness at between 28K-36K. No reason to think they'd leave much behind.
By the same token, Kitchen notes that Jericho has been subject to tremendous erosion, fire, and reuse of building materials. So how much would survive from the time of the Conquest?
There are tricky debates of the identification/location of places like Ai. However, these villages are only about the size of a city block.
So there are lots of reasonable explanations for why we don't have archeological corroboration for some of these sites or events.
vii) At the same time, there's a surprising amount of archeological corroboration of Scripture. Surprising considering the fact that Israel and 1C Christians were politically insignificant, so we wouldn't expect ancient historians to say much about them in the first place. Not to mention how little has survived the ravages of time. Likewise, archeology has only scratched the surface.
viii) By contrast, there doesn't seem to be any archeological confirmation for the Mormon "scriptures." For instance:
The Book of Mormon tells that a small band of Israelites under Lehi migrated from Jerusalem to the Western Hemisphere about 600 B.C. Upon Lehi's death his family divided into two opposing factions, one under Lehi's oldest son, laman (see Lamanites), and the other under a younger son, Nephi 1 (see Nephites).
During the thousand-year history narrated in the Book of Mormon, Lehi's descendants went through several phases of splitting, warring, accommodating, merging, and splitting again. At first, just as God had prohibited the Israelites from intermarrying with the Canaanites in the ancient Promised Land ( Ex. 34:16; Deut. 7:3), the Nephites were forbidden to marry the Lamanites with their dark skin ( 2 Ne. 5:23; Alma 3:8-9). But as large Lamanite populations accepted the gospel of Jesus Christ and were numbered among the Nephites in the first century B.C., skin color ceased to be a distinguishing characteristic. After the visitations of the resurrected Christ, there were no distinctions among any kind of "ites" for some two hundred years. But then unbelievers arose and called themselves Lamanites to distinguish themselves from the Nephites or believers ( 4 Ne. 1:20).
The concluding chapters of the Book of Mormon describe a calamitous war. About A.D. 231, old enmities reemerged and two hostile populations formed ( 4 Ne. 1:35-39), eventually resulting in the annihilation of the Nephites. The Lamanites, from whom many present-day Native Americans descend, remained to inhabit the American continent. Peoples of other extractions also migrated there.
That's putatively an Iron Age culture. What metal implements would we expect to survive from that place and period?
What about pottery, stone buildings, &c? A Hebrew equivalent to Mesoamerican Indian civilizations (e.g. Inca, Aztec, Maya).
What are the estimated population projections for that time period?
The putative terminus at quem is about half as long ago as the Exodus and Conquest. So we'd expect more to survive.
ix) Worse still, the problem with the Mormon "scriptures" isn't merely lack of corroborative evidence, but counterevidence. For instance: