iTunes and iTunes U provides audio and video programs related to the history of photography, the photographic industry, and much more.
Many podcasts, particularly those accessed through iTunes U, are recorded by professionals from around the world. An examle is Jeff Curto's History of Photography Podcasts, which have been in production since 2006.
Here is an example of a streaming video with David Griffin, Photo Director of National Geographic, discussing photojournalism. This video is provided through Films On Demand.