In this photo provided by CBS, talk show host Keith Olbermann, left, chats with host David Letterman on the set of the “Late Show with David Letterman,” Tuesday April 3, 2012 in New York. (AP ... more 
In this photo provided by CBS, talk show host Keith Olbermann, left, chats with host David Letterman on the set of the “Late Show with David Letterman,” Tuesday April 3, 2012 in New York. (AP Photo/CBS, Jeffrey R. Staab) MANDATORY CREDIT; NO ARCHIVE; NO SALES; FOR NORTH AMERICAN USE ONLY less 
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Associated Press | Photo By CBS, Jeffrey R. Staab
Tue, Apr 3, 2012 8:49 PM EDT