In Reference to Mickey's Philharmagic, I think we are passed the age of straight-up 4-D Shows. With every blockbuster on the block getting released (or in some cases Re-Released) in 3-D in theaters across the country, they have lost their novelty.
Now that 3-D is being used for depth, (Exactly as it should be) rather then putting things in your face, I think we probably won't see any more new shows where you just sit a theater and watch a 3-D movie, regardless of in-theater effects. But instead 3-D incorporated into any rides requiring screens. (Transformers, Spider-Man, and I think eventually Simpsons and possibly even Potter, would be great examples)
That being said, I actually came up with a concept for a new kind of motion simulator. For those of you who are familiar with the Simpsons Ride at Universal, I would love to see that same basic concept but in 3-D and with Kuka Arms. You would load just like and audience in a theater, and each set of four seats would raise up, and then be able to have a full range of motion during the show. I came up with this concept for a Spider-Man attraction, which links these two concepts together nicely. Mostly because I would love to imagine wind in my face while swinging through the streets of New York with Spider-Man on the Kuka Arm to get a real suspended swooping feeling.
As far as other Marvel Rides, I partially designed a Marvel area for a park I've been working on for about a year now, and in included a traditional roller coaster themed to Iron Man/The Avengers, That 3-D Spider-Man Kuka Motion Simulator, and a dark ride themed to the X-Men.
If you're familiar with the X-Men you've probably heard of the Danger Room, a training room in the mansion which uses alien technology to essentially create any environment possible. My concept is to bring guests face to face with the X-Men's most famous villains, while fighting alongside the mutant superhero team in a training mission.