FDR's fireside chats succeeded partly because he understood the nature and potential of radio, but mostly because he leveled with the American people about the challenges they faced (together) and the importance of their support in making the New Deal work. If Obama takes the same honest, forthright approach, he has a good chance of making a similar connection.
FDR's triumph was a moral triumph before it was an economic one. He demonstrated, with the support of the people, that democracy would survive this unprecedented challenge. Italy had abandoned democracy, Japan was suppressing anything that looked like democracy, and Germany was going off the fascist deep end. But the United States would remain democratic regardless of the economic hard times.
Democracy today isn't challenged so directly. But if Obama can demonstrate that the American system is responsive to ordinary Americans, and not just to Wall Street, during these hard times, he will be off to a very good start.