Recently i've been getting into Marvel comics. I've been reading Dark Horse comics (Star Wars, Conan, etc) for a few years but last week I picked up a copy of Marvel 1602 by Neil Gaiman and it blew my mind. One of the ways i'm getting started in the universe is by watching all of the recent movies: Iron Man, Hulk, Ghost Rider, Spiderman, the Fantastic 4, the X-Men etc, and i've noticed that recently (post Iron Man) they're all connected in the lead up to a new Avengers movie.
My question is this: if they're all connected, does that mean that films earlier in the 'modern' era can be incorporated later? For example, could the new 'Thor' movie alluded to in the post-credit scene of Iron Man 2 see a guest appearance by Hugh Jackman as Wolverine? Will Captain America meet Ghost Rider? And when Nick Fury meets Luke Cage, will the screen explode?
The problem, I guess, is that every movie has previously existed inside it's own continuity. When Dr Doom attacked the Fantastic 4, one could hardly expect Spiderman to have come swinging in, even though logic dictates that he should have. Unfortunately said logic also dictates that the original Ghost Rider is also General Ross from The Incredible Hulk, so I don't know how well that will work out for Sam Elliot's schedule.