YouTube is massing and hosting far more educational content than how-tos and demos. The University of North Carolina Chapel Hill now has a dedicated portal for lectures, talks, and interviews: http://www.youtube.com/uncchapelhill.
Videos range from professors giving intimate talks, prominent speakers presenting large lectures, and interviews that probe scholars’ research and teaching. UNC's recordings and some simple metadata are uploaded to YouTube and appear on the UNC “channel.” The volume is impressive: There are now more than 250 videos in different playlists on the UNC channel. I read in a press release (posted to the ASIS list, http://mail.asis.org/mailman/listinfo/asis-l) that the UNC/YouTube relationship proved so successful that channel management is transitioning to the Dept. of University Relations, although colleges will continue to add lectures. The interesting twist to me is the University's generosity with this content: the videos are free and available for use classrooms, home-schooling, research, and more, and the school encourages use and reuse of the materials. Times are a-changing!
Stanford, Yale, UC Berkley
Stanford, Yale, UC Berkley are also doing quite a bit as well, they have i-tunes site set up for content as part of i-tunes U.