If you ask me ET's days are numbered and it would better serve Universal to level it and use the massive amount of land to create new attractions. Take a look on a map, you knock down ET, Fievel, Animal Actors, Barney, Woody Woodpecker, and Curious George you have an enormous amount of real estate.
In turn you "could" do this,
Dreamworks Land complete with Madagascar Play area, Shrek M&G, and a HTTYD themed show
Bikini Bottom with SpongeBob flume ride and massive water play area.
Just brainstorming here but you get the idea. ET is a thing of the past and attracting younger families is the next phase.