This seems to be the key to all of this. If the source was not Rove, it is not likely that it was anyone else in the White House. Novak referred to "Administration Officials", not specifically "White House sources", so it does beg the question, why is Miller willing to go to jail to protect her source? I doubt that it is on principle You have nailed it perfectly! ...my thoughts exactly.
And the Old Media is strangely quiet as to questioning her source since hers must be different if she is in jail.