My views are pretty radical on this, which is why I don't see anyone ever awarding me a doctorate.
I'm for the total disbandment of a regularly scheduled lecture time. Instead, there will be a schedule of "class hours," which students may attend whenever they wish, where the professor is obligated to attend, and will speak about whatever it is the class wants to talk about. It would be essentially the same as a professor's obligation to have office hours, only in a larger room to include potentially more people at once.
What would be required attendance, then, are one-on-one appointments in the professor's office. The student will receive personal feedback on his work and the progress of his studies. The professor will show him exactly his mistakes and give him an opportunity to correct them by assigning extra work focused in these areas. This work will be optional, effectively allowing the student a freedom of choice over his grade level (do the work until it's right or accept being mediocre). Those who are already doing well will be offered advanced work for credit in another course. Students who would want to finish the course in a shorter amount of time would be able to. Students who would want to finish the course in a longer amount of time would be able to.
Lectures as we know them will be an artifact of the past, archived instead as digital webcasts to watch, fast-forward, rewind or completely ignore at a student's discretion.