The one comment I'd make off the top of my head is that his rhetorical strategy of invoking, in a positive way, the Founders and the Constitution and suggesting that their general vision was right even though it was corrupted by slavery, will lead some to (rightly I think) compare this talk to King's Letter from Birmingham Jail. King's use of Biblical imagery as well as references to the Founders gave that document much of its rhetorical power by calling whites to account by their own value systems.
To be clear, I'm not saying that it is the equivalent of King's Letter, just that this rhetorical element may bring forward those comparisons.
Obama's explicit comparisons between the anger of Wright's generation and how it plays out in African-American churches and the anger of white Americans about ongoing economic change (which Obama has misdiagnosed, but that's another story) or perceptions of reverse discrimination seem to come from a similar sort of place: I understand why you are angry and you need to understand why we are angry and, by your own ideals, you should want to recognize the source of our anger and join in addressing it.
In any case, the speech will continue to get talked about and we'll see if my prediction about comparisons to King's Letter hold up.