In this discussion, the elephant in the room is being ignored: People have difficulty discerning Link's sex.
It is quite evident that Zelda Wii U will feature a Link that is significantly more effeminate than past games, to the point of creating confusion of whether this Link is male or female, or if it is Link at all. This directly points to a unisex appearance, where the sex cannot be easily discerned. You don't do this sort of thing unintentionally, this isn't a chance decision.
Aonuma teased about the topic too. In doing so, he shows exactly the above. He once more underlined that he does not Link to be so clearly defined, and that he wants Link to represent the player.
The new design, along with Aonuma's words make me believe that Zelda Wii U will feature a unisex Link (or genderless, or gender-ambiguous, or any other equivalent). Link has always been 'elvish' but this time this is clearly taken one step further. This time Link blurred the lines.
I think that this time, Link will be able to be seen as both. When the design is made in such a way, that people can't be sure of what they see is male or female, we have a unisex design that can be seen as both naturally. This is evident by the reactions spotted in discussions surrounding the topic. People have difficulty discerning, they need someone to tell them "What's the sex of this Link" and Aonuma replies with teasing and with talking about not clearly defining Link and representing the player.
On a more practical level, look at the design. Assume you know nothing about Link other than what you've seen in this trailer, what do you see? If people did this earnestly, I believe we'd get many different responses. That's exactly the point. By being ambiguous, this Link lets themselves be seen in any way. Wii U Link may lack breasts but that doesn't mean Link can't be female, just as not having facial hair doesn't mean Link can't be male. The other parts of the body will never be shown. This all leads to one thing: Interpret Link's sex as you want. It is left up to the player to interpret it. The player's subjective perception will be what decides Link's sex this time, not a pronoun (which Japanese can and does throw out of the window by the way), not obvious sexual characteristics (which don't exist on Wii U Link or are otherwise unknown, and impossible to know).
I believe this is revolutionary. I may be reading too much into it, but all that has been shown points towards this. I think it's genius. Link's Wii U design transcends the boundaries of sex and gender into the domain of unisex and personal interpretation and perception takes the scene. It's an incredibly creative opportunity that I am convinced Aonuma has identified and taken with the new design.
As to the matter of inclusiveness, a unisex Link is infinitely more inclusive than any female Link, any male Link, or any "pick your sex Link". It's also an original and innovative way of presenting a character in a very broad context. There are precedents in Japanese pop-media. People often slander anime, manga, JRPGs and the like, but unisex or effeminate-male or masculine-female characters are not at all uncommon. There is also a clear precedent with Link's designs. Everyone knows that Link is elf-like, that possesses "feminine" traits but it also that brave young boy, countless games attest to that. In this new game however, I'm seeing something different and I believe it is intentional.
The design is vague, Aonuma's wording is vague, the teasing is vague. That's because Link's sex this time is vague. People will be able to project onto Link what they feel as a person and that will, in fact, actually fit. Link looks like either because Link is neither but can be either or neither or all at once. The design doesn't have to be binary, it doesn't have to be either male or female and that's exactly what the design expresses.
I won't accept this being wrong unless Aonuma flat-out denies all of this and the Japanese release uses sex-specific pronouns.
Otherwise, It's pure genius.