The first two are hardly tied to WoW specifically, or have anything to do with gameplay. And I'm pretty sure the BattleTag system was made more for Diablo 3.
I'll give you dual specs and the cross realm stuff, but transmogrification is not innovative. Games have had A-Tabs forever. That's all it really is, an A-Tab you have to sink more gold into.
So once again, they added innovative stuff in a 7 year time span.
The sarcasm of my post was pointing out that it's not hard to do.