My thoughts exactly, John. Remember that a doctor in Florida emerged after all this happened and recalled he treated one of the hijackers not long before the attacks for a condition, that while he didn't pick up on it at the time, looked to him in retrospect like Anthrax exposure.
My guess is the gov made the Iraq link to the anthrax a long time ago, but didn't want to tip its hand until they were ready to act. Keep him guessing and off balance, IMHO.
And at least two Anthrax experts from Johns Hopkins agree that it was an Anthrax infection....