The anthology was finally released on blu ray without the longer TV cut of Superman.
I was surprised that according to a review they actually bothered to include the 35mm mix in 2.0 on the blu ray of the theatrical cut, i don't have a blu ray player and have no way of knowing if the 5.1 is another new mix or the 70mm mix which all have been waiting years to hear again.
Any news on the release status of this project would be welcome.