Now Francis Watson of Durham University has come out and has argued that the fragment in question is most likely a modern day fraud in which the author has simply taken phrases from other Coptic Gnostic writings and stitched them together to make a provocative statement.
Richard Backman also notes that the fragment in question is composed in Coptic, which is unlike the well known Nag Hammadi writings, which were translated from Greek into Coptic. Thus suggesting that even if the fragment is from ancient times it is derivative of writings translated from Greek and hence is a late text.
Watson also notes in his summary (p. 6) that one of the eight lines within the fragment follows a line break which is identical to how it is presented in another text which is preserved in modern editions.
In its time Coptic had no spaces between words, and when a word reached the end of the line unfinished it simply continued in the next line without any hyphen. Seems odd this fragment exactly follows the one other example known to scholars of these Coptic writings. Here are Watson's words:
The impression of modernity is reinforced by the case in line 1 of dependence on the line-division of the one surviving Coptic manuscript, easily accessible in modern printed editions.
Unless this impression of modernity is countered by further investigations and fresh considerations, it seems unlikely that GJW will establish itself as a “genuine” product of early gospel writing.
This story has already reached the Guardian.
Also here is a blog about this which, while I certainly don't agree with everything he says, provides a complete transcript of the fragment in question.