It depends on your kids and when you're going. We went for 1 day in Nov with two 4 year old girls and a 1 and a half year old girl from about noon till closing at 8pm. Saw the Little Mermaid, Beauty and the Beast, Disney Jr., and Frozen sing-along shows, had lunch at Hollywood and Vine w/ Disney Jr., rode Great Movie Ride, Toy Story Spin, Star Tours, Tower of Terror, and saw the Osborne Lights, and they all loved it
We didn't get to do the Muppets 3D movie, The Animation Building, Honey I Shrunk the Kids play ground, or Fantasmic, didn't think our girls would care for the Indy Stunt Show, or Lights Motors Action, and weren't tall enough for Rockin' Roller Coaster
There are a few different character meals at the other parks and resorts, if that's you main reason for going to DHS, and last summer they had something call Pirate and Princess Summer at the Magic Kingdom with Jake and The Neverland Pirates and Sophia the 1st, but I don't know if that is happening again this summer