From the Jeremiah Wright controversy to the Rick Warren uproar, I think we've learned that whoever Barak Obama chooses as a spiritual representative/advisor, some portion of the population will be outraged. If this makes him decide to avoid including religious leaders in public ceremonies and/or to attend church infrequently, people will say "See, he's not really a man of faith. He was just pretending in order to get elected." He's in a no win situation on this, I think.
However, the next time he wants an experienced, articulate pastor from Southern Californian to speak at a significant event he could pick, well--you know . . . :)