Have you seen the construction photos that have been leaked? Considering how close to completion this ride is, it looks to me like a bunch of concave screens surrounding a track. Which says to me they're not even attempting to theme anything in the ride itself, they're relying entirely on the film to tell the story, making it little more than glorified simulator or a variation on Spider-Man.
Speaking of which, while I agree with the sentiment that Spider-Man is a fantastic ride, I hesitate to say it's the best ride out there. They've maintained the effects on it very poorly (as they have with most of the attractions at IOA) and I haven't ridden it in the last 3 years without something not working. And not something little either. I've ridden through it at times when half the screens weren't projecting correctly or the audio wasn't working in the vehicles.
To say that Disney has never topped it isn't necessarily true. I consider Pooh's Hunny Hunt and Journey to the Center of the Earth to both outdo Spider-Man (and yes I've ridden them both). While this may not count to many of the Disney visitors on this site or in general, it certainly is fact that Spider-Man hasn't been top dog in a while.