They suggest he knew Wright wasn't going to go over well with the public. He intended to distance himself from Wright. He rescinded an invitation for Wright to speak at his presidential announcement saying, "You can get kind of rough in the sermons, so what we’ve decided is that it’s best for you not to be out there in public." (Source:
http://www.nytimes.com/2007/03/06/us/politics/06obama.html) Obama attended the church for 20 years and admits to hearing controversial and disagreeable things (though he's yet to specify what they were). His camp also stated, when the story first broke that they didn't intend to take Wright off the campaign, suggesting to me that Obama didn't have the serious problem with the statements that we have been led to believe. The firestorm of criticism that grew up around the pastor is what did it, IMO, not any great moral integrity on Obama's part.
Now Obama's actions seem to me that Obama knew Wright's comments weren't just the occasional off hand remark expected by most preachers. If they were, as Obama tried to imply in his race speech, he would have felt no need to distance himself or have any anxiety about Wright.