I love the music.
A few points to pick up on, might expand on these later (meant to be marking essays currently):
Link fighting side by side with another character. Follower system, or a hint at multiplayer?
Two female figures, presumably significant. Is one Zelda, and another a female Link? Are they both Zelda? Is Zelda playable instead of Link? Did Aonuma lie to us? Multiple playable characters?
Dog!
Link has what looks like the Master Sword, when he's stood on a platform/boat and the bird-creature flies past him. I am assuming you can find and restore the Master Sword. The big question is: is this an essential part of the quest, or optional?
Bird-creature/flying city. Ruto? Ooccoo? New race?
Hyrule Castle Town being destroyed by Calamity Ganon.
The shots in-between in-game footage looks like a close-up of old parchment, or another animal-based paper like material. Is this a prologue telling us about Hyrule? Could be a similar narrative device to the tapestry in Wind Waker, and the cave painting in Skyward Sword.
There's a lot packed in there.
EDIT: The most significant thing I noticed about the Let's Play (apart from disappointing frame rate), was that in order to find the shrine, you needed a clue from an NPC about environmental landmarks. The lack of way-points was encouraging.
