The best article I've read on Presidential Inaugurations remains Ted Widmer's piece in the American Scholar from 2005. The entire thing is a treat but he handily summarises the essential rules of Inauguration Speeches as:
1. I am not worthy of this great honor.2. But I congratulate the people that they elected me.3. Now we must all come together, even those of us who really hate each other.4. I love the Constitution, the Union, and George Washington.5. I will work against bad threats.6. I will work for good things.7. We must avoid entangling alliances.8. America’s strength = democracy.9. Democracy’s strength = America.10. Thanks, God.
Given how venerable the inaugural tradition is, it is becoming more difficult to claim, as so many presidents have, that we are a very young country. We are more like an aging movie star who needs a couple extra minutes to apply her makeup. “Getting old ain’t for sissies,” as Bette Davis said. But age has its compensations, not the least of which is that our history just keeps getting better. The inaugural ceremony is already crowded enough, but for me there will be forty-two other presidents on the platform, adding their voices to the sounds of the ceremony and straining to “harmonize in the ancient music,” to use Seward’s discarded phrase. Surely it does no harm to pause for a moment and listen to what they have to say, still speaking to us faintly over the din of the republic.
Lately there's been a change, however: The American people are, I think, ready to embrace, even if just for a day, rhetoric. That's been out of fashion for some time. Clinton was too slick, too much the southern snakeoil salesman to ever have you believing in his rhetoric. (You'd ask, where's the catch?) and, well, it wasn't really George Dubya's style. But it's precisely because the US finds itself, it fears, in a mess that it's willing to put its trust, indeed its faith, in a young man from Illinois who, yup, happens to be African-American. And so the temper - or the chill - of the times has rhetoric back in vogue.