The newest trailer of Breath of the Wild solved the mystery of the female blonde character from the last trailer in December. It was all Zelda! Again, it felt like Nintendo was playing with the audience on purpose with all the rumors about a playable female Link going on. But that should be out of the question for Breath of the Wild, because this game again builds heavily on the relation between Zelda and Link, as you can see in the newest trailer with Zelda crying in Link's arms.
They already tried to achieve something similar with Skyward Sword, where I even made a post about the cute Zelda at the time and how she's more of a character that you might want to save, instead of some far away princess hidden in a castle or dungeon, who you have never even met before. However, this didn't really work out so great. The beginning was lovely, but ultimately Zelda then just spent her time in the game running away from you, instead of running into your arms. And she grew quite a distance to Link, when she became aware of her role as the incarnation of Hylia. This kind of ruined the whole approach and hopefully their relation will be more fulfilling in Breath of the Wild.
It also still looks like she has a more active role in the game. She wears the same blue "uniform" as Link and she might even have her own Sheikah Slate, though in the trailer only of them has one, so there might only be the one Sheikah Slate. In the above scene Zelda has the Sheikah Slate, while Link carries the Master Sword. Even though Aonuma denied a playable Zelda at E3, it really looks like it's a possibility at this point, where you take the role of Zelda for a part of the game that focuses on "Wisdom" (the puzzles), while Link brings the necessary Power and Courage.
But it also looks like that both Link and Zelda come from the same time and were put in stasis for those 100 years in between. Here it's possible that certain scenes from this trailer and the last one are simply flashbacks, which is a theory that already came up in December from channels like GameXplain, but I'm not sure, if I would like the game to jump between the times as much. I'd rather explore the mystery of what happened hundred years ago in the present.
I'd also prefer an approach, where Zelda has a more active role in the game and you can switch to her, if you need the Sheikah Slate, or where both go on their separate missions. However, this would feel needlessly complicated and maybe even limiting, since Link can just do it all. He can use weapons and the Sheikah Slate, there's no need to split this between two characters, unless you want to perform certain actions at the same time. But then again this might be complicated to control. So, in the end I'm not sure, why Zelda has the Sheikah Slate in the footage.
In any case, they seemingly tried to make Zelda more loveable than ever with her new look. Those big eyes (and eyebrows, haha) create this emotional connection, where you want to care for her... Even more so the heartbreaking cry in the trailer. I personally like this design more than her Skyward Sword look with these goddessawful bangs. And while her Twilight Princess design was amazingly graceful, she felt too cold and distanced in that game. In Breath of the Wild she looks cute and serious at the same time. I'm not entirely sold on the new looks just yet, but I do like her more than the Skyward Sword incarnation.