Hell, why not go for a twofer and have +Gene Robinson give the benediction; piss off the left on one end and the right on the other. And the irony is that on certain matters of history, theology, and doctrine, Bishop Robinson is actually MORE conservative than Warren.
I would even prefer to see the elderly Billy Graham wheeled out on a gurney to the inauguration than listen to Warren.
Despite the inevitable Democratic Party leadership tone-deafness to the feelings of its most inconvenient but reliable constituency, LGBTs, I'm still "punched as pleased" to see Obama become the 44th President of the United States of America.
Elizabeth Kaeton has a very good, measured, and thoughtful post on Rick Warren at the Inauguration here.