Vacationing in Rome during E3 means my flow of information is limited, but from everything I've seen and read so far, it seems like people are only commenting on the graphics, and not pointing a finger or Wiimote at the Kinectimals sized elephant standing in the room: the actual Skyward Sword's connection to the story. I think there's still another big secret that hasn't been revealed about the actual Skyward Sword item yet: it will let you fly.
Many years ago, Miyamoto was adamant that he only involves himself with creating new Mario and Zelda games when there's a huge new aspect of gameplay to explore. So, naturally when I saw the Legend of Zelda: Skyward Sword trailer end with Link jumping off a cliff, and then read the title of the game to be Skyward Sword, a few things began to click. All of this is just speculation of course, but hit the jump and consider the following things.
Update: More evidence added at the end of the article.
Look at the left side of the picture above. Figuring out that the girl was a personification of the Master Sword was a no brainer for most people last year, but look at her again. Her cloak looks really really wrinkled. Almost like wings. And look at the handle of the master sword in the teaser video. They've always meant to portray wings, but they look even more ruffled this time.
Then look at the right side of the picture above. Yes, this Hylian crest has been around since pretty much the dawn of the legend in the Zelda series, yet it's pretty dang vivid and pronounced behind the title text. In previous games we saw a wolf behind the title text, because a wolf was integral to Twilight Princess. With Wind Waker we had a boat stapled behind the title text for obvious reasons. This time, we have a game about the sky over Hyrule, with wings plastered in bright colors behind the game's title, and the main item of the game is called the "Skyward Sword" and the trailer ends with Link seemingly jumping to his demise off a cliff. Hint hint?
My first prediction is that Link will eventually have permanent access to upgraded hover boots (think Roc's feather!) in the form of the Skyward Sword. I'm expecting it to work like an umbrella (expect a lot of Mary Poppins jokes!), where you can make Link jump off cliffs in the game, and then you hold your Wiimote up in the air, and in the game the sword will split into two wings that let you levitate or float for a while. I suppose the best description would be permanent access to one of those chicken-jumps from Ocarina of Time. Some support for this theory is the fact that the sword can draw energy from the heavens by pointing it to the sky.
My second prediction stems from the lack of Epona in the trailer. I'm not saying horse mounts won't exist, but I am saying that flying mounts in a game like this is something I'm really expecting. Possibly a pegasus, but more likely a bird of some kind -- thus the Hylian shield crest originates from a "Hero of Time in the sky." To make a Zelda game like this without letting the players fly around a level at some or many points in the game would be like not putting a boat in Wind Waker. It seems almost necessary that the sword or a mount in the game will let you fly. A flying beetle or seagull isn't enough; I want battles in the sky on the backs of flying mounts as storm clouds crack lightning all around Link! And an instrument that can control the weather! Okay now I'm getting greedy, but I'd bet all of my rupees that a flying mount will happen. It just better not be that damn owl!
My final prediction is that this entire game's plot will be the explanation for why it's important to keep the Master Sword hidden from Ganon and the rest of the world: it can literally fly you to the heavens of Hyrule. Hopefully fans will finally get to play the infamous sky temple they've always longed for!
The fact that this game won't be released until 2011 might be a reason for keeping big aspects of this game under lock and key for now. Revealing them later on right before the game's release would definitely raise the consumer excitement levels for the game all over again.
Perhaps I'm just looking up and seeing objects in Hyrule's clouds that don't exist? You be the judge. What do you think?
Updated evidence: Eiji Aonuma has said this about the new Zelda Wii game: