I think I would find it inappropriate if say, Star Wars' miniatures of the Millennium Falcon or Death Star sat next to the Mercury 7, but the Enterprise's real and imagined history makes it a natural for the exhibit.
Ooh, them's fightin' words, in some circles...fortunately I don't move in those circles!
Just want to mention to everyone - I'm not trying to put forth an opinion myself here - like I said, I'm not sure which I'd like more. I'm looking forward to seeing the conservation work though!