As you all should know, the game has a light world and a Twilight realm - areas of Hyrule that have been engulfed in a dark shadow of evil. Apparently, light is returned to Twilight-covered areas of the game by "hunting down shadow insects and collecting the tears of light they've consumed, restoring one of the four great Light Spirits."
The preview discloses interesting details concerning Link's abilities in wolf form. "As a wolf, Link controls almost exactly as he does in human form; every attack has its equivalent. Dashing with the A instigates a burst of speed, and though he cannot access items, D-pad shortcuts allow him to dig and access his senses."
These senses are used to detect digging spots, shadow insects and spirits of Hyrule citizens. These spirits apparently do not engage in conversations with Link, but you can sort of listen to their mutterings, no doubt to gather essential information.
It is already known that Link transforms into a wolf when in the Twilight realm. But Edge interestingly reveals that: "Link can also re-enter the light-world in the form of a wolf. There, people fear him but he can talk to animals."
Link's relationship with animals plays a huge part in many areas of his quest. As well as the return of Link's horse, Epona, who he can summon with a horseshoe-shaped reed, he will also interact with a hawk (again summoned with a reed), which he can launch at meddling monkeys or bees' nests.
Some of the mysteries behind Midna, the strange character riding on Link's back when in wolf form, have also been answered. When teamed with Link, Midna will apparently take on a Navy-style role, offering helpful hints and tips as the player explores. She can also help out with battle, conjuring a force field around Link that can instantly destroy groups of enemies in the Twilight realm that will otherwise revive each other.
Edge also reveals the existence of "a highly unusual character called Ooccoo - a chicken homunculus with a human head - who appears in dungeons, takes residence in your inventory and allows you to warp out and return to exactly the same spot, should you need supplies."
Edge was is full of praise for Twilight Princess. Yes, we're all going to buy it anyway, but that's always encouraging. Will it be better than Ocarina of Time, though. All evidence seems to suggest it might just be...