Alan Dershowitz has posted a defense plan for Scooter Libby that seems like such a winner that it is hard to believe that Fizgerald does not have some plan to counter it. Libby will insist that classified documents are needed for his defense, have the governmental entity refuse to provide them and then claim that the charges must be dismissed because he has been denied the right to present a defense. After all, this is not Gitmo!
Mr. Dershowitz seems to have inspired a cacophany of personal attacks, but my memory is that this has worked for someone in Iran Contra. The only reference I could find online is to Joseph Fernandez, who was cut loose in 1990 when Richard Thornburgh refused to release supposedly secret information. I remember from the time that the classified nature of the information seemed questionable. Of course, the Bush I administration abandoned all pretense two years later when the President, after being defeated by Clinton, pardoned the whole sordid bunch on December 24, 1992.
Update Suntzu below may have the answer, which would be that Fitzgerald has more power because in this case Ashcroft, and presumably Gonzales, disqualified themselves so Fitzgerald has the Thronburgh role here. If anyone has more information on this, please comment. For example, does any governmental agency have the right to keep things secret even over the demand of the Attorney General? Does anyone know if Gonzales is disqualified? After all, we have had prosecutors fired before if they got to close to the President. (I'm sure you know this suntzu, but your thirty-one year old colleague was not born yet) I suppose that is one reason that Fitzgerald's tour de force press conference was helpful.