I think of it simply. A "going forward" thing. So, most things in the past aren't going to result in a new attraction at Disney World. But new things that are done by Disney COULD.
Also, the agreement is fairly new and given the length of time for Disney to plot and plan and imagine a new attraction, it could be at least two-five years for anything Marvel related to appear.
I'd rather have Disney do an full experience than just slap up a roller coaster and say IT'S MARVEL! IT'S HERE!