A picture of a hundred (or so) words is worth more than when they were spoken:
Obama's word cloud
Lambert's cloud formations, comparing Obama's words to FDR's, is self explanatory.
Update - While I agree that the word clouds are drawn form different kinds of speaking events (a closed conference and a public address respectively), the patterns of language are what fascinate me. In a smaller venue with members of the ostensible intelligentsia, I'd expect to see more substantive language. Given the condition of the economy, I'd expect to see a lot of terms addressing that topic. What I see is vapidity. With a national speech, I'd expect to see more generalities, more platitudes. Instead, I see action words, things asking people to do things or talking about paths to be taken. There is also a broad range of words that are emphasized more or less equally, in comparison to the verbal imbalance of the former.
I'd like to see the speeches reversed or to have a more recent president compared to Obama. If that's done, I'll link to it. Update - Please look in the comments. CMike has posted a set of links to word clouds of different president's inaugural addresses.