Katie Couric will interview Sen. Joe Lieberman today in Washington, D.C. to air tonight on the CBS Evening News. It's his first interview since it was announced he will hold on to his chairmanship of the Senate Homeland Security Committee.

Couric will be back in New York by this evening, and will appear on the Late Show with David Letterman.

The last time Couric was on Letterman, she didn't know it. It was September 25 as she interviewed Sen. John McCain on the Evening News set. Letterman aired parts of the pre-taped interview and blasted McCain for canceling on him, only to appear with Couric.