Textual Criticism of the Qu'ran?

Here's an interesting article in the Asia Times Online regarding textual criticism of the Qu'ran. Some may have already heard of this, but allegedly ancient manuscripts of Islam's holy book were hidden away, and are only now resurfacing and available for scholarly scrutiny. Spengler notes:

It has long been known that variant copies of the Koran exist, including some found in 1972 in a paper grave at Sa'na in Yemen, the subject of a cover story in the January 1999 Atlantic Monthly. Before the Yemeni authorities shut the door to Western scholars, two German academics, Gerhard R Puin and H C Graf von Bothmer, made 35,000 microfilm copies, which remain at the University of the Saarland. Many scholars believe that the German archive, which includes photocopies of manuscripts as old as 700 AD, will provide more evidence of variation in the Koran.

Why is the presence of variants in the Qu'ran significant? After all, in biblical manuscripts countless variants are known to exist. Again, Spengler:

No one is going to produce proof that Jesus Christ did not rise from the grave three days after the Crucifixion, of course. Humankind will choose to believe or not that God revealed Himself in this fashion. But Islam stands at risk of a Da Vinci Code effect, for in Islam, God's self-revelation took the form not of the Exodus, nor the revelation at Mount Sinai, nor the Resurrection, but rather a book, namely the Koran. The Encyclopaedia of Islam (1982) observes, "The closest analogue in Christian belief to the role of the Koran in Muslim belief is not the Bible, but Christ." The Koran alone is the revelatory event in Islam.

This article is especially interesting for what it proposes as an explanation as to why Germans circa World War II contrived to keep such manuscripts shrouded in secrecy. (HT: Dan Reid via Evangelical Textual Criticism)