They were expecting Rev. Wright to deliver the inaugural invocation? Joe K is correct about the politics here: With Rick Warren, Obama will project a veneer of cultural conservatism, but a "compassionate" cultural conservatism that will be open to cultural radicalism.
In the meantime, Obama nominates leftist Member of Congress Hilda Solis for Secretary of Labor, a third-rate pick for this second-rank Cabinet post. This allows me to note one of the best books on Washington politics ever is by Solis’s Clinton Cabinet predecessor, Robert Reich, Locked in the Cabinet --available used for the price of 1 cent (plus s&h). Its description of the chaos of presidential transitions makes it a must-read for those insights alone. His confrontations with union bosses are painful and hilarious.
By the way, anyone keeping an eye on the number of Catholics Obama has picked for positions, starting with Biden?