Yes. Something else is going on here. I've worked as a journalist and have been asked to reveal my sources. However, to be asked to reveal a source when I hadn't even published a story would be quite an invasion of privacy.
Newspaper reporters have stories and background information leaked to them all the time. If it is too controversial, not pertinent, or has no supporting sources -- you just don't use it! I can assure you that any reporter worth her salt has a thousand stories and supporting details stored in her head and in her notes. But if you haven't printed it, where's the crime?
Something doesn't add up about why Judith Miller went to jail. The New York Times reporter didn't write a story about the Valerie Plame case and had a waiver from her source in order to talk about it to the grand jury. But she insisted on going to jail anyway. Speculation is mounting that Miller is protecting herself, that Miller was herself a source of information about Plame that made it to several Bush administration officials and was then recycled to columnist Robert Novak. He, then, disclosed Plame's employment by the CIA and her role in arranging for her husband Joe Wilson's mission to Africa to investigate the Iraq-uranium link.
This would help explain why Miller didn't write a story about the case. It would be difficult for Miller to write a story when she was so deeply involved in how it developed. Disclosure of her role then or now would be extremely embarrassing.
She could be the key to exonerating Bush administration officials of possible violations of the law against knowingly disclosing the identities of covert intelligence agents. If they were simply passing along information from Miller or some other journalist about Joseph Wilson's wife, then they can't be accused of deliberately disclosing classified information about Plame's identity.
The more likely explanation is that Miller is protecting private discussions with administration officials, and that during those discussions she provided or confirmed information about Plame's identity. This would make sense. Both Miller and Plame covered the subject of weapons of mass destruction and it was likely that they knew one another, or at least were aware of each other's work in this field.