Intrade has Obama trading upward today, presumably on generally favorable reaction to his speech in Philadelphia. This graph is going to be a little hard to see, but...
What this shows is that Obama was trading at about 77% to win the Democratic nomination this time a week ago. Those numbers dropped down to about 72% after the Wright controversy reached full volume. And now, post-speech, they seem to have stabilized in the 75% range.
So Intrade's snap conclusion is that about 60% of the damage from the Wright controversy (Obama recovered 3 out of 5 percentage points that he had lost) was redeemed by today's speech.
I'm actually not a huge fan of futures markets, by the way -- I love the concept, but think they lack both the liquidity and the highly informed pool of traders to make them truly useful as predictive tools. And I think futures markets really tend to be lagging rather than leading indicators. But, they can be a pretty interesting way to put a quantitative spin on the conventional wisdom.