I and others have pointed out some problems with this supposed inscription and I still just cannot see it. None of these problems are even mentioned in the PhysOrg piece, but Mark Goodacre has an excellent new post on the subject at the NT Blog: Do the lines in the "fish" head spell out Jonah? (The link to James Tabor's post defending the reading is currently glitched in Mark's post, but you can find it here.) In addition to the problems with the reading already flagged, Mark points out that the CGI image produced earlier by the team dealing with the ossuary sees the supposed letter nun as two separate lines (as I also saw it here), which makes it not a nun at all. As Mark says:
It is not just sceptics of Tabor's and Jacobovici's claims who are struggling to see the name of Jonah spelt out here. It is the project authors' own CGI picture, designed before the new claim, that bears testimony to the difficulty in seeing the letters that they now wish to see.If Professor Tabor wants to convince his colleagues that there is an inscription there and that it says "Jonah," he needs to take up the objections one by one and demonstrate that (1) the lines he says he sees on the ossuary, especially those of the "nun," are really there and as he sees them and (2) that each supposed letter shape can be closely paralleled by specific letters in other Herodian informal lapidary inscriptions such as appear on ossuaries.
Perhaps more to the point, the argument needs to be made in an article that is accepted and published in a peer-review journal. Blogging and press releases are fine, but journals and monographs are where substantial advances are made in the field.
Background on the whole Jesus Discovery/Talpiot (Talpiyot) Tombs discussion can be found here, here, and links.