I just discovered that Norwegian Qumran scholar Årstein Justnes was blogging about a seminar on this text as early as May.Søren also has a post on the text is his own (Danish) blog, PergaMent.
Not much is added to what you've already blogged concerning the content of the text, but it is reported that ideas in the seminar varied as to the genre of the text (Torleif Elgvin: "prophetic/charismatic", Magne Sæbø: "midrash", [J.J.?] Collins: "Quais-prophetic" )
Justnes, however, has severe doubts about the authenticity of the inscription (and he is not prone to doubting authenticities all over the place). He gives five reasons:
1) peculiar language with "artificial" expressions
2) unfocused and incoherent content
3) ink-on-stone is a previously unheard-of writing medium impossible to date by C14
4) provenience unknown (except for the vague "east of Jordan")
5) clever forgeries have been copious lately
Personally, I'd say 5 is irrelevant until proven relevant, 4 is highly deplorable but hardly decisive, 1 and 2 could point either way (as my old teacher Fred Cryer used to say, "a new inscription that does NOT have oddities but is done strictly acc. to Gesenius/Kautzsch -- now, THAT's suspicious") -- but 3 is certainly interesting.
I've now skimmed through the Cathedra article and looked fairly carefully at the transcription of the text. The language is peculiar (1) and the text is pretty incoherent (2), but I would have to spend a lot more time on the inscription (more than I have to devote to it any time soon) before I would be willing to take a position either way on its genuineness. On the one hand, my default position is to be suspicious of unprovenanced inscriptions (4, 5), but on the other, Ada Yardeni is not a paleographer easily fooled by fakes (3).
UPDATE (30 December): More here (next post).