I just learned about this from a member of my astronomy club. Michigan Tech University is offering an introductory astronomy class this semester (PH1600), taught by Professor Robert-J.-Nemiroff. The lecture videos are available through iTunes U and as direct downloads from Learnoutloud.com.
I downloaded the lectures available so far and previewed parts of the first one, and it seems like a solid, college-level introductory astronomy class. One unusual thing about it is that there is no textbook, or rather that they are using Wikipedia as the text book! As the professor explains in the first lecture, the on-line resources for introductory astronomy are quite strong and are typically more up-to-date than any paper textbook. Required reading includes the Wikipedia articles on Universe, Electromagnetic Spectrum, and Light Year. They will also use NASA's Astronomy Picture of the Day as a continuously updating resource on astronomy developments.