Well,
At the Magic Kingdom, we most need something in the 20K site besides a meet and greet. Some sort of dark ride, I would hope. As noted above, it would be interested to see if Disney can do a dark ride from scratch! Also need polishing of COP. But I do NOT want to see Nightmare Before Christmas at HM (I suppose it would be okay Nov-Dec.) OR Jack Sparrow in POTC. We just need to polish these as well.
At Epcot, Living Seas nees help. I haven't seen the Nemo overlay yet, but it needs help. Of course, going back to original JII would be my preference. WOL needs a revamp, although I would prefer to keep both Body Wars and especially Cranium Command. I think the Ellen story line improved UOE.
What we really need here is a new country. Haven't had one since Norway back in 1988. There are plenty of available ideas, with rides available. There have been plans for Spain (not just that little promo thing they did a couple of years ago), Switzerland, Russia, Israel and Equitorial Africa.
At MGM, I'd love to see the Indy ride replace the Indy show. I don't think that would require as much (any?) parking lot sacrifice. I'd also like to see another versiion of SuperStar TV, with updated shows.
At AK, we need rides, rides and more rides. And NOT Triceratops Spin! There is a wealth of raw material available and apparently plenty of land.