You know, I was thinking about the cruise and it not being the first actual sailing...and I think that you will be glad you are doing this one and not the first few.
I've been on a TA & Christening cruise before, and it was quite crazy...I then went on the "first" sailing right after, and it was smoother, and more fun! On the cruises prior to the Maiden, not everything will be fully functioning...in fact, I was told that there is a good possibility that some things won't be open. And just think of the PARTY on the Maiden, with all of the excited guests!
If I were you, I would look at it as the Maiden being the first REAL voyage of the Disney Dream...the first time the new, gorgeous ship will be full of devoted Disney guests that planned and dreamed for months if not years about being on the first voyage. To me, this is the first voyage...the others are testing it out...like test driving a car, but the guests on the first voyage are the "owners"
I'm not saying things won't still be a little crazy or disorganized, because there is a good chance of that...but Disney does things better in general so I'm guessing they'll do this well too.