Jon Stewart is the host of The Daily Show which airs on Comedy Central every weekday. Last night he most likely made news commentary/journalism history by hosting President Barack Obama on his show.
Clearly Stewart is a news commentator rather than an actual journalist, but he still does inadvertently give the news to some people who use The Daily Show as their only source of political information. And I think Stewart respected those people by actually asking President Obama some tough investigative questions. By having the president on his show Stewart is setting new boundaries on how seriously the average adult should take these comedic news shows.
Clearly President Obama is using The Daily Show to reach otherwise unavailable parts of the constituency (mostly younger male voters). And while it may cause Walter Cronkite to turn in his grave I truly believe this will be the new format the public will want to see and will see for interviews in the future.