Mike Allen at Politico has a fuller preview, based on a conference call held on background for reporters held Monday:

Calling for America to show a new maturity that will bridge old squabbles, President-elect Obama plans “a sober speech” for bleak times, leavened with assurance that he believes better times are coming, aides said.

Obama will call for “a new era of responsibility, and will talk about both the “price and promise of citizenship, the aides said. 

A senior official said Obama’s inaugural address, to be delivered before a massive, cheerful crowd stretching more than a mile down the National Mall, “balances a serious and very sober tone with a dose of hope and inspiration that we can get through this.” 

“He will buck up the American people,” the aide said. “There’s a substantial dose of hope and inspiration in there.” 

--Jonathan Cohn