The fact that the griping classes in both the Christianist and gay camps are in full indignation mode about this is probably a sign that Obama calibrated his choice perfectly.
My take on this, and on pretty much anything Obama does that at first doesn't sit right with me, is that Obama is a black man who was just elected president of the United States, which must make him like the smartest person in the world, politically speaking, so why don't we just relax and give him the benefit of the doubt instead of jumping all over him about which preacher he picked to say a prayer at the inauguration. Yeah, he could have picked a lesbian Unitarian, and that would have pissed off about 90% of the population. Rick Warren only pisses off about 3%.
I kind of like the notion of a Evangelical bigot being compelled to bless the presidency of Obama, whose election basically says to Warren and his people, "Your time is up."