AVAST MAYTEE, THAR BE SPOILERZ AHEAD
5.4 has come and gone, and aside from a rather embarrassing snafu involving having NPCs rate female player-characters on appearance which two other blogs have adequately covered here and here, it seems to have gone mildly well. As for the cinematics....
First, to provide context, I recommend watching the videos; Alliance and Horde respectively:
So a long time ago, in a post far far away I criticized Blizzard's story writing style for essentially ignoring the player characters. They might have their reasons for it, but I always found it a bit unsatisfying in WoW that the raid that defeated the boss would not even be mentioned in the cinematic of their defeat. For the most part, the players barely make the cinematic, if at all.
I ended up sighing when I noticed that this continued in Pandaria; with Garrosh's defeat making no mention of the players or their involvement. We don't even get a Star Wars Episode 4-esque "Medal Ceremony" scene despite how many times the raid saves the world. I can't speak for the fight but at least this time it does appear that the players actually get to DOWN the boss (as opposed to a random story NPC that is SOOooOOo much cooler than you getting to do it). This isn't stuck to WoW, the player character got a half-hearted mention in Diablo 3, and again in the Diablo 3 expansion trailer ("Find the nephelem..." which begs the question, "Where did I go?") as the NPCs Blizzard love get the credit and the player perpetually plays the Kiff Kroker to their Zap Brannigan. Fixing their messes while the NPCs strut.
Alas I suppose programming a scene to react to the players is a bit much to ask, but some recognition might be nice.
Still, the cinematic seems to set up Expansion 6 or patch 5.5: Varian's turn to lose it. I was kind of surprised in the Alliance version just how much of a 180 Jaina has pulled since the whole Theramore thing. Back in Wrath she was the one keeping the peace....not any more it seems. Even then, as a former Alliance player it is weird to see the NPCs that used to preach peace out suggesting violence...though I'd be even more offended if it was Valen (though Blizzard seems to have forgotten about the Draenei leader and race; like the cousin at a family reunion with the face-tattoo, they seem inclined to pretend he doesn't exist).
I'd almost bet money that the next expansion or major patch will be: Kill Varian, his son takes over.