Some (even on the right) are saying Obama gave a pretty good speech. Others are considerably less generous. (transcript) I just don't see much to get excited about one way or the other.
Sure he glossed over finer aspects of "the religion of peace", and turned the Barbary wars on their head, and implicitly suggested Thomas Jefferson had been sympathetic to Islam, but that's not too different from what Dubya would have done. Anybody could nit-pick this speech to death. But overall, he didn't say much that hasn't been said before, and most of it will be ignored and irrelevant by next week.
Obama's relying on the idea that he's the one delivering it. (And he's also trying to fulfill a campaign pledge to give such an address.) This is where the rubber hits the road on The One's ability to get things done with diplomacy. Color me skeptical.