With the 4 minutes I got to play, so far my opinion of the story is - fucking awful. Not necessarily the content per se, but it reminds me of those movies where you are introduced to shit that makes no sense and the fanboy reply is 'oh you have to read the comic or novella that leads up to the movie and it all makes sense!' No, I fucking do not.
Unless I completely missed it, there's nothing in the game that goes over the events of Garrosh 'Kill' cutscene -> WOD Intro cinematic. Then you have the launch event...which is just kill Orcs that somehow appeared. Now, mysteriously, young Khadgar is here. Why? He couldn't have come through because the other timeline was not after he closed the dark portal (and he wouldn't have been younger). Everyone was tossing around 'oh bronze dragons and Wratharion blah blah' but that's bullshit, because it wasn't in the fucking game. It needs to be IN THE GAME. I sort of expected something to make sense with the WOD intro crap, but no... just talk to Young Khadgar who... NEEDS YOU TO KILL ORCS BAWWWW YEAAAAAA.
Blah. Reminds me of an EQ2 expac for story. Here's some zones and dungeons and more AA... just go kill shit and stop bothering us.