I'm re-posting this. Here is my dream lineup of how I would hope they finish out the Hogwarts Castle line, across the next two years.
Hogwarts Castle: Clock Tower - Provides one or two sides of the quad behind the Main Tower, and connects to the Hospital Wing. I'd like the clock tower itself to be relatively film-accurate when viewed from the front or the back, so we get the iconic exterior and courtyard while also not revealing interior play features when viewing the Hogwarts model from the front. I'd suggest that the top level of the tower should have the full grey roof visible from both sides, while the bottom half (which will be hidden behind the Main Tower set) could be open, either displaying a classroom or two or the swinging pendulum. If LEGO chooses to fully enclose the quad, this set could be L-shaped and offer three classrooms, mirroring the Hospital Wing set. I'd love to see another version of the Defense Against the Dark Arts classroom, providing additional iconic elements. So perhaps this set could include Moody's class (with foe glasses, the blackboard, and some spiders) and the Prefect's bathroom? I like the idea of each large set including a big fig, and these rooms that I picked are Goblet of Fire themed, so I'd pick the Hungarian Horntail for this one.
Hogwarts Castle: Lockhart's Class - A modular classroom set that features more iconic Defense Against the Dark Arts elements, such as the dragon skeleton, the pixies, the small balcony, and Lockhart's giant portrait.
Hogwarts Castle: Astronomy Tower - A thinner but tall set, including several thinner rooms, stacked vertically. It can optionally connect, via a suspension bridge, to the side of the Hospital Wing set. It would be Order of the Phoenix and Half-Blood Prince themed, including a Room of Requirement (Dumbledore's Army style), Divination class, Umbridge's office, the Slug Club party, and the Astronomy class at the top. Perhaps a small jail cell for Sirius' escape, and we could get a Buckbeak big fig.
Hogwarts Castle: Viaduct Entrance - This would be a smaller set, similar in size to the Hospital Wing, and it would connect adjacent to the Astronomy Tower set. On the top floor would be the library with restricted section, and the Slytherin common room in the basement. Perhaps a potions storage room or Snape's office also? Bloody Baron for this set!
Hogwarts Castle: Chamber of Secrets - A lot of people think that the Chamber should be under the Viaduct Entrance. I'd prefer to see more of the right side of the castle, completing the whole facade. I'd prefer for the Long Gallery and Bell Towers designed to be a large Chamber of Secrets themed set. The Flying Lesson would finally have a connection point, and this set would connect to the Viaduct Entrance set. On the upper level would be Moaning Myrtle's bathroom and the "The Chamber of Secrets Has Been Opened" hallway. Under Moaning Myrtle's bathroom could be the entrance to the Chamber, with the iconic door and bones. The wider section of the basement would include the walkway with snake statues and the large Slytherin head statue. The big fig would be the basilisk.
Hogwarts Castle: Battle of Hogwarts - The stand-alone viaduct that connects the Viaduct Entrance to the Great Hall. This set would include several Deathly Hallows minifigures, including Voldemort, Harry, Neville, and Nagini.
And just because... Hogwarts Castle: Whomping Willow