WoW died when they tested the Alpha of Vanilla obviously, everything else has been an elaborate and lengthy funeral in it's honour. Ok I'm kidding, it died when people started talking about WoW on forums.
Though on a serious note, I find the mmo market is pretty saturated as most practically feel like the same game just with a new skin and title name. Not exactly going to set the world on fire, nor grab new players. Think the worst thing FF14 did was not keep the FF11 style (which in itself is very similar to me as ff12's combat), as by adopting the more recognisable WoW UI (I know WoW wasn't the first mmo to have said UI but go with me on it) I feel they reduced the uniqueness that could've set it apart. Side note always felt ff12's combat style would've lent itself to an mmo with a few tweaks due to differences between mmo and single player game.
The next mmo that makes a big impact will likely be an mmo that doesn't look like WoW or any other mmo currently around, as in order to draw players away from the more traditional mmos someone is going to have to risk a flop and make something that feels different than what is already out there.