"Just to clarify...the Dallas production of Superman has an entirely new libretto"
There have been new librettos for this show a few times and none of them have been good. You would almost have to write a completely new show. I haven't seen this one so I won't pre-judge, but I am sceptical.
I saw the show yesterday and found it to be rather enjoyable. It was not perfect by any means, but the book of the show was very strong, I think. The rewritten book and character arrangements worked very well and made a spectacular show, considering the fact that it is a SUPERMAN musical. After the show, a friend and I were the only ones at the stage door. We spoke to Jenny Powers and right before she went off for dinner she smiled and said, "We'll hopefully see you in New York." and laughed. Hopefully this may imply something is going on with the production and its transferring?