If the contention is that Bush is trying to do a power grab, that contention doesn't make a whole lot of sense if he's going to be out of office soon and could be replaced by someone in the opposing party.
I didn't read the entire directive, but I didn't where this gives the president the powers of a dictator.
(6) The President shall lead the activities of the Federal Government for ensuring constitutional government. In order to advise and assist the President in that function, the Assistant to the President for Homeland Security and Counterterrorism (APHS/CT) is hereby designated as the National Continuity Coordinator. The National Continuity Coordinator, in coordination with the Assistant to the President for NationalSecurity Affairs (APNSA), without exercising directive authority, shall coordinate the development and implementation of continuity policy for executive departments and agencies. The Continuity Policy Coordination Committee (CPCC), chaired by a Senior Director from the Homeland Security Council staff, designated by the National Continuity Coordinator, shall be the main day-to-day forum for such policy coordination.