I think Ed is wrong on one point:
This scroll is not very sexy (c'mon — Leviticus?), and therefore it is probably authentic. A fake scroll would have mentioned Jesus or Paul and been offered for sale to the Israel Museum for $5 million, after a breathless article touting its importance had been published in BAR. But I'm glad they're doing tests on this one.
Anything to do with the Bible is sexy and any biblical manuscript at all is very sexy. The potential market for forgeries isn't limited to Christians, and Leviticus is a foundational document for Judaism. And it might seem like a better strategy for a forger to make a quick, smaller profit on fragments of a biblical book than risk more attention and more vigorous reprisals from a faked blockbuster.
I hope the scroll is genuine, but I'm keeping an open mind right now. I do know that Hanan Eshel would not be easily fooled, so if this scroll is a forgery, it's a very good one. We'll see.
UPDATE: In an update to the same blog post, Ed Cook grants my point about the sexiness of Leviticus and adds the following:
I am wondering, though, if ancient animal skin suitable for forgery can be easily found. Other forgeries on stone, ceramic, or papyrus are less easily detectable since uninscribed ancient pieces of these materials are common. But truly ancient animal skin suitable for forgery must be rare (but I speak under correction). I agree that we should be cautious.
Agreed about the ancient animal skin, but do we know yet that the skin is ancient? It doesn't sound as though the fragments were authenticated before the sale. The seller has the money. Can he be traced if it turns out to be modern leather? How difficult is it to make modern leather look ancient?
If the leather does turn out to be ancient, I'd say it's extremely likely that the scroll is authentic. I truly hope that I'm just being a pessimist and that the tests will show this to be the case.
Speaking of unauthenticated scrolls, whatever happened to the so-called "Angel Scroll"?
I e-mail Stephen Pfann in March to ask if there was any news. I did not receive a reply.
UPDATE (19 July): On the g-Megillot list Joe Zias comments on the precedent being set by paying the looter for the fragment. He is not pleased.
Also, and I just knew this was going to happen, Google is now referring people to PaleoJudaica via the search term "sexy."