We didn't move them to EdX, we just made them private and available to Berkeley students only. I think this is because of some rulings stating that lecture videos have to be provided with CC if they are to be made public (OCW was sued for this).
It's a shame that a better solution could not be reached because it was very nice having recent course videos available (as opposed to many EdX courses which use 5-10 year old videos).
More directly, could one volunteer to transcribe the lectures into a CC-like format so that the lectures could be safely and legally be put up for public consumption?