Today at BlizzCon, Blizzard President Mike Morhaime has announced that players who commit to a one-year subscription to World of Warcraft by purchasing an Annual Pass will have access to Diablo III.
This isn't some kind of full game trial like on PlayStation Plus, but the whole shebang as a digital download. An Annual Pass also grants WoW players the Tyrael's Charge mount. To say that this will bolster numbers for Diablo III is an understatement, though we might a sudden drop in Annual Pass membership in a year once players are all sucked into Diablo III.
Still no release date for Diablo III has been announced.