Now we all know that Sandboxes are the one-true-way of the highest expressions of RPG mastery, but... not everyone wants the same thing. There's been discussion about what is needed as an introductory product to draw new players into oldschool D&D-ish games; what kind of experience do most contemporary (non-mmo) computer & console RPGs offer? What kind of expectations would some kid off the street have regarding fantasy adventure?
There's no reason that an Adventure Path has to be a tasteless save-the-world railroad. It can be a series of interconnected sandbox-ish environments with an overarching narrative. A picaresque pulp serial instead of Dragonlance.
Now, just as a thought experiment, imagine an Adventure Path released by a respectable, quality OSR publisher. An Adventure Path that has a grand caper as the overarching structure, a treasure hunt, perhaps the pieces of a treasure map need to be assembled; a series of MacGuffins that need to be collected before one can get their paws on the super-super MacGuffinf?
I'm imagining an Adventure Path in the vein of Ulysses, Odysseys, and Sinbad. A mysterious sea with a variety of fantastic and bizarre islands. As most published and homebrew campaign settings include oceans, and most also do not describe the entire world, such a setting should be easy to shoehorn into an established campaign world.
Imagine such a path with episodes written by Gabor Lux, Matt Finch, James Raggi, Geoffrey Mckinnley, etc...