But Hearthstone doesn't fall in that category. Not at all. It is NOT casual enough to replace Crazy Birds (stupid game too) and it is PvP based with a very (boring) hardcore surrounding these days.
Nope, not a lot of women will be attracted to it. And nope apart from the usual "gamers" crowd it won't enter general public acceptance either.
Part of that is due to the PvP kind of seeding, part of it is that HS is the wrong kind of game to be played for months long.
Will it penetrate the giant smartphone market? Nope. Can it be a hit on tablets? Let's hope for Blizzard, but frankly I think the "vogue" will be very limited, because most people will get owned by the hardcore crowd.