It seems that Matt Cooper had already testified about his conversations with “Scooter” Libby (Cheney’s chief of staff) about Valerie Plame. Libby apparently had released Cooper from his pledge of confidentiality (which answers the question previously debated in the blogosphere about the asserted futility of such releases), and Libby was apparently the only potential leaker the prosecutors wanted to hear about from Cooper.
The notes in dispute apparently contain information about another source or sources, who might turn out to be innocent witnesses to the affair rather than one of its perpetrators. If so, then the court order does indeed create a precedent making legitimate newsgathering more difficult, and Cooper does indeed have a professional obligation to protect those innocent sources. I’d still doubt that his obligation gave him an adequate moral warrant for ignoring a lawful final court order, but your mileage may vary.
I’d be disappointed, after all this huffing and puffing, to get no one higher on the totem pole than Libby, but we can’t know whom he might turn in once he’s really facing a long prison term.
Updated to correct a misinterpretation of the underlying news story pointed out by a reader.