People are always complaining about DHS and how it is a half-day park, so I am curious on what you think needs to be added to make DHS a quality full day park. I have listed my suggestions below.
Log Flume or River Rapids Ride- DHS is the only WDW park to not have a water ride (not including shows) where riders have at least a chance of getting wet (Splash Mountain at MK, Maelstrom at EPCOT, and Kali River Rapids at DAK). A ride where the rider gets wet is very nice on a hot Florida day.
Roller Coaster with Mild Speeds (2)- Rockin' Roller Coaster is a great ride, but it is the parks only roller coaster and is usually not suitable for little children or people who don't like inversions. Two rides, if possible, with speeds similar to Big Thunder Mountain Railroad would be nice.
Land/Area Based in a Movie- It doesn't have to be Cars Land or even Star Wars Land, but an area that puts visitors in a different world from a movie is always an instant hit. My personal opinion is Monstropolis, since it hasn't been done yet, and put Star Wars Land in a hero/villain based theme park, but it doesn't matter.
An Interactive Game Show- It would be great if DHS had a show that was based on a T.V. game show, like Fear Factor Live at USF, but with a popular show.
More Recent Films to the Great Movie Ride- There are no remotely new movies on this ride, and the current generation hasn't heard of some of the movies on the ride.
Current T.V. Show Sets- Replace Honey, I Shrunk the Kids with a Mickey Mouse Clubhouse for kids, or with a different popular T.V. show set for kids