Royal Skousen, professor of English and Linguistics at BYU, has been working on a a critical text project of the Book of Mormon (BOM) for two decades. He now presents the results in The Book of Mormon: The Earliest Text (Yale, 2009). Yale University Press offers this cloth-bound, 800-page tome for only $35.
Skousen has examined the textual variants among the earliest BOM sources. He presents a corrected text that aims to approach as nearly as possible that dictated by Joseph Smith to Oliver Cowdery and others in the late 1820s. Unfortunately, the textual variants are not provided in a textual apparatus at the bottom of each page, but are found in an appendix. Skousen presents the text in "sense-lines," breaking up the text in phrases and clauses.
I must admit that I am not very familiar with Mormon Studies, but I suppose that a project like this, published by YUP, is highly signficant for this area of study. In the Journal of Book of Mormon Studies, vol. 15/1, available on-line here, there was a more extensive "interim review" of Skousen's work by five Mormon Studies scholars.
Here is a recent reader's review, reflecting the reception of the book in LDS circles.