Two years ago, Sal Khan and John Hennessy (president of Stanford), went to a conference and talked about the future of education: http://allthingsd.com/20120531/how-do-credentials-change-as-...
They both concluded that lectures may not exist in the future!
Sure, there are such things as lectures that have oratorical brilliance, that inspire students about their subject. However, for the most part, lectures are just inefficient ways to get information across. With the Internet, we have methods to get this information asynchronously, without requiring packing everyone into a room.
Rather, the role of the teacher in the future will be supporting students. That's where humans outshine computers - answering questions, tutoring, understanding where students might be confused, etc.