Just a couple of thoughts. The speech wasn't great. It continued in more subdued form the twisting of the truth (see, for instance, the lines on energy) and mockery regarding Obama that has been the main theme of this convention. McCain gave a nod towards overcoming "partisan rancor," but apparently hadn't heard the rest of the speakers at the convention, including the utterly nasty Sarah Palin. On the policy proposal side, it traded in generalities as convention speeches do, and had a couple of downright weird moments (would we get rid of unemployment insurance under a McCain presidency?). The speech was, overall, pretty pedestrian.
But the final part of the speech, the now-standard retelling of his POW story and how he overcame being a selfish ass, was well done. It's a compelling story. It's just not nearly enough to be president.
One more thing... to McCain's merit, he finally showed a little of the touch of why he might be considered someone who sometimes goes against the grain (i.e., "maverick"). His call for reform in government didn't target "liberal elites running Washington," as others at the convention have had it incessantly. He targeted Republicans equally. This is an important move in terms of regaining some of the integrity of character he's supposed to possess after having allowed his campaign to become starkly Rovian. It thus lends some concreteness to the maverick theme, which has otherwise remained abstract throughout the campaign.
Perhaps most importantly, while one may disagree with the possible policy methods and overall ideological positions, it's a move back towards the core of that "thoughtful conservatism" I mentioned earlier (in a post on Biden), which it shares with thoughtful progressivism. This opens a more serious path to the presidency largely by backing off his un-mavericky appeal to the base that the selection of Palin represents and by tapping into the wave of dismay with the status quo that has led many voters to Obama. Afterall, he has got to overcome that Buchanan line I mentioned earlier - "The Republicans are running against a Washington that they run" - by carefully distinguishing Republican rule that's moribund, and sometimes criminal, from a version (ostensibly his own) that shows genuine promise for reform.