I feel like Universal may go Wicked over LOTR to save on licensing fees - the Emerald City and rest of Oz would look fantastic with Potter level detail. You could do a lot with Oz (dark ride, family coaster, Splash Mountain-style flume, musical venue, walkthrough, etc.)
It'd be cool if they split the big plot between Wicked and something else. Hill Valley (maybe with portals to depict 1885, 1955, 1985 and 2015) or a general sci-fi area could be cool additions that add something different.
For Universal Monsters, an Amity mini land would be fun to bring back a revamped JAWS ride. The Creature concept would also be good.
Pikmin, Animal Crossing and Kirby (one or two of the three) would be a good toddler/preschool focused mini-land to add by Nintendo after Luigi's Mansion - a Fantasyland style dark ride, a couple flats, a M&G, and a play area. With the Mario and DK rides all having height requirements, it'd be good to have some Nintendo stuff anyone can go on.
Another striking flat ride concept for the whole family could be cool for Celestial Park.
The flying theater for HTTYD would be a good way to round Berk out with a major indoor ride for when it rains.
For Potter, I'm not sure. It seems like the area is pretty tapped out.