Before that Mitt Romney, Mike Huckabee and Rudi Giuliani spoke to the delegates, although they strongly went after Barack Obama and vouched for McCain's candidacy, their speeches could all be condensed to this theme: During the last 8 years (and please do not think of Geroge W. Bush or a Republican Congress most of that time), the world has gotten much more dangerous and the only person who can save you is John McCain.
As for Sarah Palin, I am not sure if expectations had been set so low that by just showing up, she was going to exceed it. However, whatever your feelings about Palin, she gave a very well prepared and delivered speech. Does that mean she is qualified to be president on January 20, 2009? I don't know, the voters will decide on November 4th.