Bill Burkett has been the most likely source of the CBS documents. Today, his lawyer said the following:

Based upon my personal knowledge of Bill Burkett's character from knowing him and knowing of his reputation among his peers, I will state unequivocally that Bill Burkett did not falsify or create the "CBS documents." I do not assume that anyone falsified or created those documents until more is known, but if anyone did, it was not Bill Burkett. I will stake my reputation and good name on this certainty. Further from my knowledge of Bill Burkett's character and integrity, I will state unequivocally that if, hypothetically speaking, Bill Burkett handled documents that were recent creations rather than true copies of originals, he would have done so only because he had reason to believe they were true copies rather than recent creations.

Later today, the AP reported:

CBS said Burkett acknowledged he provided the documents and said he deliberately misled a CBS producer, giving her a false account of their origin to protect a promise of confidentiality to a source.

And down we go into the spinning vortex of lost credibility of almost everyone involved in this story. This amazing. I'm waiting with baited breath for the next revelation.