No, what WoW did offer was consistency, simplicity, and ease of use.
The Problem is: this alone isn't enough anymore. Look at WoW today. When you want to attract the wow crowd you can't just make a copy of wow classic. You need to make a copy of the game today and add some really interesting features. The very best try was rift(in my eyes). It's the only mmo who comes close to what a good mmo needs in our days. The only problem is, that they have no big name like blizzard.
The other example is sw:tor. It's even simpler than wow. Also uglier(in terms of art direction), full of boring quests(the type wow had at release), boring flashpoints(unpolished, full with boring trash mobs, repetitive and boring boss fights) and stoneage gameplay. Even Daoc hat more interesting classes and skills to offer and thats why even the lightsabers weren't able to help them out of this.
So the biggest mistake a company in our days can make is to believe that simpler = better. Don't try to make a simple game like wow even more simple. Thats what blizzard trys since cataclysm, too. And the only thing they get are more and more leaving customers. In fact you should go back to blizzards old virtues.
Three very easy things, every mmo creator should not forget:
1. "Easy to learn, hard to master!",
2. "Polishing until it shines like the sun!".
3. "Its better to bring a fresh and good idea of someone else to perfection than to have your own ideas!"
The problem many mmo creators have is that they try this but fail at the end because they betray this virtues. For example because they run out of money or because its too hard to make or whatever. And thats the reason why so many fail to copy wow. Also think about the creation of wow. Yes, blizzard copied already existing ideas. But compare the market 8 years ago to the market today. We had about 2-3 big mmos. Everquest, Daoc, Ultima Online. And only a hand full of smaller ones. Blizzard copied their ideas and made something really big. What SW:ToR made: they copied the same ideas, but 8 years later, and brought it to an already oversatisfied market but also failed to follow the three virtues. If you want to be successfull you have to make it better. Dont just make exactly the same thing as dozens of developers did since wow did it.
You have to
understand what blizzard did. It isnt enough to just copy the same things which blizzard copied. Take a look at your features and think about where to look, and not just look at stoneage games like everquest/daoc and think they are the nonplus ultra source of everything.
Combat: pseudo-turn-based-mmo-combat(like wow) is getting more and more old. Look some other combat approaches. God of War, Witcher2, Tera and even Skyrim. This is the direction in which you should look.
Character Development:just take a look at skyrim(completly open character development), eve online(learning while offline), morrowind or champions online(movement modifiers instead of/additionally to mounts, like levitation, fast run), Diablo 3(unlockable skills and skillmodification, depending on level, skill level or something similar)
Gameplay:Tera(pseudo-physics for magic and arrows), rift(class variation(if you want hard-coded classes at all)), wow - wrath of the lich king(synergies in talent trees(without talent trees) for a better theory crafting experience)
Gameworld:UO(Interactivity), Skyrim(Open World aspects, size, borderless exploration).
PVP:Eve Online(PvP needs a meaning, like defending or conquering player-property), DaoC(large scale battles)
Itemization:Diablo 2(still the best if done right, nobody likes the paranoia-balanced item system of diablo 3), skyrim(for items found by exploration), rift(artifacts all over the world).
And so on. Just think in this way. Not in the way of sw:tor which was a 60% copy of wow - burning crusade. It doesn't get better just because you try to make what blizzard but did with a blizzard game.