He'll be talking about the "Crossfire" incident and the media in general.
From CBS' Website:
"Cable news, says Stewart, has become a street fight instead of civil discourse. "What has become rewarded in political discourse is the extremity of viewpoint," he tells Kroft. "People like the conflict. Conflict, baby! It sells. 'Crossfire!' 'Hardball!' 'Shut up!' 'You shut up!'"
http://www.cbsnews.com/sections/60minutes/main3415.shtml