It seems there will be a lot actualy. We can imagine at least one from each of the new race zones (not counting the intros) and the 5 man in Vashj'ir has a quick "cutscene" as well.
I expect they are adding a lot more than the two in Wrath =). Most likely when major phasing occurs. Pretty exciting.
I just updated my video card and monitor and went back to watch the original teaser cut scene from vanilla wow. The Dwarf hunter and the bear in the snow is still so impressive, 5 years later.
There is a zone you can see with the sandbox, that is the maelstrom. IT was posted on the main page a few days ago. I hope that will be a spot for a cutscene!
I hope so as well. I'm particuarlly looking forward to that delicious high-quality one that they have for each expansion that you can view from the starting screen.