At the Smithsonian. I'm happy they're finally doing away with that awful 1991 paint job (which everyone hated), but the analysis of the model itself is very interesting.
http://www.startrek.com/article/guest-blog-smithsonian-update-on-enterprise-studio-model-restoration
http://www.startrek.com/article/guest-blog-smithsonian-update-on-enterprise-studio-model-restoration