Tech Demo for the game
Although it is currently untitled, the set release date is 2014 (most likely we will be seeing this at E3 this year).
It was also stated that this game will be the biggest and most expensive project Nintendo has ever done (with one of the biggest teams they have ever had a on a game on it). They stated the world and soundtrack would be bigger and although there would be a similar amount of dungeons as before, these would be, "vastly bigger in scope and vary greatly" (It was said that the test run of the forest dungeon of the game was bigger than Hyrule Fields in Ocarina), it was also said some of the dungeons will be broken up into 3 parts because of their size, each part taking hours to complete.
Here are the details stated by Nintendo of the forest dungeon in the game, “The first test dungeon they made was a giant forest running on early and buggy Wii U hardware — the dungeon was bigger than the Hyrule field in Ocarina, and the whole thing is one dungeon. You use the gamepad to navigate, avoid traps, follow clues etc. It’s dark, lush, with a ton of trees, foliage, some which you have to cut your way through. Its scope and details are unlike anything you’ve seen in a Zelda game”
As for online play Nintendo states, “Online multiplayer was never on the drawing board, they’re sticking with the tried and tested Zelda formula. It’ll have some online features like Miiverse and some sort of system where players can leave hints and help each other in the dungeons. That’s about it”.
And as for the game pad implications in the game, “everything in the game is built around the controller and its unique abilities. Every single feature in the controller is used to its full potential. Some of this stuff is still in early stages of development, but they’ve already implemented enough to show just what’s possible with the new controller. They showed some of this stuff to key third party devs behind closed doors last year to get them to realize the possibilities of the new tech.”
Also some more encouraging words spoken about the gameplay, "It’ll have some revolutionizing gameplay. It has stuff that would never be possible on any other console, and it’s not just one cool feature, it’s one cool feature after another. Each dungeon will offer a different gameplay experience with the tablet controller. It’ll be the most innovative game ever, they got stuff that will be copied by others for years.”
The game will feature a "grown up" Link, it was also stated the game will be in in full high-definition with a new, "state of the art graphics system which was built from the ground up", and will feature, "the most advance visual features Nintendo has ever made". It will also use many third party technologies like Havok and Umbra. It was also said the Zelda clip you saw at E3 2011 was just a technology demonstration by a different team using an older engine. (So it's safe to assume that was just scratching the surface.)
The game is looking like it's going to be coming out late 2014 or early 2015. It was said that they were ready to show it at E3 this year but chose to wait.