I am not sure how long it has been there, but over at the Evangelical Textual Criticism blog there is now a poll on whether the Pericope Adulterae in the Gospel of John should be included in our Bibles.
I am not a text critic so I am not qualified to discuss the finer details of it, but there is a dilemma. Namely, we are pretty sure it is not an original part of the Fourth Gospel yet, to quote the TCGNT, "the account has all the earmarks of historical veracity."
What do we do in this situation?
Do we take the hard line view that only the four gospel autographs are authoritative or historically reliable?
If so, how do we deal with the fact that the Gospel narratives were originally orally transmitted? Or that Jesus' ministry was far greater than the portraits we received in the gospels?
I really don't know the solution, but in any case every translation is obligated to raise the question for the readers. I must say, for that reason I do love the TC notes that go along with the NET Bible. They are far more useful than a generic "Some early manuscripts do not contain this."