Mattis in for McChrystal?

While everyone is speculating: With McChrystal in the hot seat (see previous post) some military and political bloggers are noting that, perhaps fortuitously, USMC four-star Gen. James N. Mattis, currently head of Joint Forces Command and a former MARCENT Commander (CENTCOM's Marine units), was just passed over for Commandant yesterday, and was therefore expected to retire. Afghanistan would be a step down since it would put him under Petraeus, but the Marines were doing counterinsurgency before the Army knew it existed, and his alternative would be retirement.