For our stay last week I had planned one day at Hollywood Studios and two days at Animal Kingdom. After spending one day at each, we had a family pow wow and decided to change our 2nd Animal Kingdom day to another Hollywood Studios day. For our first day at HS we had gotten fast passes for Toy Story Mania, Star Tours, and Tower of Terror. We also did the Frozen sing along and toured the Star Wars launch bay area. We finished the night with the Symphony in the sky fireworks. The things the girls still wanted to do included: Great movie ride, Beauty and the Beast, Rock in Rollar coaster, Indiana Jones and Fantasmic. We did all of those plus a second round of photos at Star Wars (Kylo Ren this time), Frozen sing along, and Star Tours.
At Animal Kingdom for one day we did all of our "must dos" except for the Nemo show.
I too thought that we would find much less to do at Hollywood Studios, but that wasn't the case for us. Its still a two-day park.