Your weariness is warranted but I don;t think they going towards an mmo monthly sub format, but towards somekind of free to play format. Think of Guild Wars, Lotro and now Age of Conan. All of those titles do it differently but the idea is to charge one time for a copy of the game, and then introduce extra features i.e. quests, zones, cosmetic changes, items, skills etc through expansions or some sort of DLC packs. I do not think they will charge monthly sub for D3 simply because it's in their best interest to have their gamers to play all of their games. They wouldn't want their gamers to be choosing to play either D3 or WoW. It's already a huge commitment just to play them, let alone paying subs for them.

How to call it "Diablo 3 MMORPG" when it's not an MMORPG?