I just watched part of the History Channel special - Star Trek: Secrets
of the Universe, and there were some nice shots from the new movie.
(high-res) close up of the Bridge at the end of the movie, in comparison to the first movie, the window appears to be substantially taller. In consequence, the area above the bridge in the original 2009 construction pictures
appears to have enough room for two decks. Now it looks like there is only room for maybe one deck.
My (personal) conclusion - ILM has shrunk the Enterprise size down by 15-20% at the end of the movie.