Sword of Spirit
Legend
He seems to be implying that the "sourcebook" is linked to the adventure, but not the adventure.
Yes, but it sounded to me like a player sourcebook, not the sort of DM material that I need.
OR...
You introduce a Campaign Setting in three stages: a GM world guide, a sourcebook/adventure guide for the world, and then an AP/module line. You could do this for Eberron, Dragonlance, Ravenloft, etc. One book gives you the world-down info, one book gives you the PC options and the "what the world is like" info, and the modules give you an ongoing storyline.
I don't expect ALL APs to be like this, but I can wager a few of them will be.
That would be perfect, but I don't think that's what he was hinting at.
I'm reading it as the psionic "sourcebook" is the player's companion book (with an accompanying chunk of dedicated material) and the adventure is the "DM's sourcebook", with monsters, treasure, DM options, and etc.
If the adventure is intended to be the same as the DM's sourcebook (and honestly, I got the same impression as you did from what was said) I'm very doubtful it would contain sufficient material. If they make a Planescape adventure path, are they really going to have dozens of pages at the end giving us MM style presentation of 7 archons, 7 guardinals, 7 eladrin, the additional 4 or 5 yugoloths needed to fill out the basics, gehreleths, hordelings, heirarch modrons, plus creatures to populate the other planes? And I'm not expecting every little odd and end ever to grace a book here--just the majority population of the various planes so we don't have to rely on fan conversions to play the setting. I just don't see them trying to squeeze a monster manual (which is what something like Planescape or Dark Sun would need) into an appendix at the end of an adventure.
What I glean from Mearls' statements about future supplements is that they'll thematically fit with the "Adventure Path" being published in the same quarter, (e.g. the "Elemental Evil" adventure path will be published close to the supplement with Genasi Races, Elemental-powered Classes, and so on) but other than that the books can just be used as stand-alone character options and fluff books, with no connection to the story arc at all.
I agree. Now, if he can figure out how to do that while presenting the DM material, I won't complain about the adventures.