I think Obama's speech was pretty brilliant, if a bit long. Of course, at the end of the day the formal speech is the area of politics in which he most excels so channelling the Jeremiah Wright controversy into a "major speech on race" was a savvy move. I think this was the most significant part:
In fact, a similar anger exists within segments of the white community. Most working- and middle-class white Americans don’t feel that they have been particularly privileged by their race. Their experience is the immigrant experience – as far as they’re concerned, no one’s handed them anything, they’ve built it from scratch. They’ve worked hard all their lives, many times only to see their jobs shipped overseas or their pension dumped after a lifetime of labor. They are anxious about their futures, and feel their dreams slipping away; in an era of stagnant wages and global competition, opportunity comes to be seen as a zero sum game, in which your dreams come at my expense. So when they are told to bus their children to a school across town; when they hear that an African American is getting an advantage in landing a good job or a spot in a good college because of an injustice that they themselves never committed; when they’re told that their fears about crime in urban neighborhoods are somehow prejudiced, resentment builds over time.
The kind of white resentment Obama is talking about here has been a problem for the Democratic Party for decades now notwithstanding the fact that you rarely see the party nominating African-Americans to run in majority white constituencies. What Obama is showing us here is that precisely because he's black, he's able to acknowledge and validate these resentments in a way that would be very difficult for a white liberal politician.
At any rate, I'd say things are back on track. The Wright business had opened up a vague sliver of hope for Hillary Clinton's campaign -- if they could produce a result in Pennsylvania that looked like a Wright-induced collapse in Obama's white support, maybe they could convince superdelegates that he's unelectable. After this speech, I don't see it happening.