I've heard that in WDW's barbershop they do special things for first haircuts. That is so cute! I agree, I wish DL would have that too. It would be a great experience.
If they have Disney wedding gowns and bridesmaids' dresses, it's only a matter of time before they come up with lingerie for underneath. I'd buy a Cinderella-inspired corset.
Also, the Miley training bras would probably sell very well.
If only there was a way to keep people from taking offense to the idea of the shop and to keep teenage boys from loitering inside...