Flip the system and make the classwork homework and the homework classwork.

Instead of a lecturer being the 5000th person trying to teach the subject with a varying degrees of preparedness, you just get the single best and most enthusiastic lecture of all time, everytime, as a video. Then in class teachers, TAs, and students can have normal humans conversations with each other to work through problems and peer interaction to motivate learning. Instead of this being relegated to additional office hours\recitations\labs.