This NYT story hypothesizes that if the I. Lewis "Scooter" Libby Plamegate charges make it to trial, it could come down to whether the jury believes Scooter or the journos.

An excerpt:

... It is all but unheard of for reporters to turn publicly on their sources or for prosecutors to succeed in conscripting members of a profession that prizes its independence.

Yet Mr. Libby's trial on perjury and obstruction charges will largely turn on whether jurors are more inclined to believe a government official who played a critical role in devising the justifications for the Iraq war or members of a profession whose own credibility has been under assault.

"We don't have much of a track record," said Jeffrey H. Smith, a former general counsel of the Central Intelligence Agency, "because journalists so rarely testify."

The three reporters all initially resisted subpoenas for their testimony, hoping to avoid not only testifying before the grand jury but also having to appear as a prosecution witness at trial. Such challenges have often been successful in the past. But all of them lost, and ultimately relented, saying that Mr. Libby had granted them permission to testify about confidential conversations.

"This is exactly the thing," said Jane Kirtley, a professor of media ethics and law at the University of Minnesota, "that journalists fear most - that they will become an investigative arm of the government and be forced to testify against the sources they've cultivated." While the special prosecutor, Patrick J. Fitzgerald, is all but certain to call at least some of the reporters as witnesses, whether they will be judged credible is an open question.