It has been brought to my attention that Diagon's Ollivanders is the horror show I have worried about. It seems that everyone will have to walk off the street not into a shop, but a long queued hallway... a hallway that is right behind the windows of the "leaked" facade we talked about a page back. So, you will basically be in a Holiday Inn hallway walking past doors to rooms that may be occupied... You might have to walk past two show doors before arriving at the third door showroom.
I was hoping for a mechanical shop swap or at least something more clever than this Simpsons: The Ride style "go to your assigned room".
I would recommend taking the train back to Hogsmeade for a more authentic experience.