When will we know? That's not an easy question to answer. Fitzgerald may have "letter" rather than formal plea agreements with them. As to those who did not receive immunity, he may be withholding his final sentencing recommendation for a downward departure from the Sentencing Guidelines until their cooperation is complete -- which may not be until the case against Libby or future indictees is over.
Libby soon will learn who cooperated in exchange for a deal. The information will be provided to his lawyers as discovery in the criminal case. But Libby's lawyers likely will be told by the Court they cannot share information in the discovery with anyone other than their client, so the media may not learn of it.
I don't believe that every person who cooperated is getting immunity from prosecution. Even Karl Rove may not know whether he's getting a total pass. I think ultimately Rove will plead guilty to a single false statement charge for lying to investigators rather a perjury count of lying to the grand jury. But he may have more hoops to jump through before Fitzgerald decides the value of his cooperation and how great a reward he should receive. If he can't get Fitzgerald to agree to recommend a downward departure to a probationary range, he probably will fight.
At some point, charges will have to be filed against those who cooperated and received less than a complete pass from Fitzgerald. That's when we will know. In other words, we'll know when Fitzgerald wants us to know.
Everyone outside Fitzgerald's office is a pawn in this game. It shows the awesome power of the Government when it decides to place someone in its cross-hairs. If the top players in the Administration of the President of the United States have so little influence, just think how vulnerable the rest of us are.
Cheney is not out of the woods. Anyone watching Fitzgerald's press conference Friday knows he wouldn't blink twice before indicting him if thought he had a provable case.
Bob Dylan once sang, "But even the president of the United States sometimes must have to stand naked." The same goes for the vice president and every one of their aides.