Actually, I'd dump ET, unless they are going to seriously upgrade it. It's old and dated. A dark ride for the family is needed, just with a different theme. And I don't mind KidZone as it is otherwise. My guys blow off a little steam, ride the waterslide (which is a cool thing to have in there), we all hit the kidie coaster, and then we can head back to real park. A little low-tech fun is a nice break. Poseidon's Fury I think just needs a whole new show script. Keep the water tunnel and a few other effects, but upgrade and get a new story.
I think what they really need to do at Uni once Kong is finished is just about all at IoA (other than the ET replacement). Other than Hogsmeade, IoA has seen no substantive additions since about 2001. Toon Lagoon needs something other than two water rides. How about a real show in the theater? A family dark ride? Or even a couple of flat rides. Seuss could use a Lorax attraction. And something on the lake. The lake now is used for nothing, and really just makes it a longer walk to get places. A show, a boat ride...something. They could even go low tech and make it a water parade like EWP.
After that, back over to USO.