It might just be the Deku Tree, but man, it looks really good.
To begin, I'll say that I'm not in the Anti-Ocarina Port camp. Since I haven't played the game in about seven years, I'm honestly looking forward to the 3DS port. The demo at Nintendo's 3DS event in New York City showed off three segments (Kokiri Forest, Deku Tree, and Queen Gohma) that showed off some of the 3DS upgrades.
First off, the game is visually impressive. I know it's basically an upgraded Nintendo 64 game, but the 3D makes everything pop, and the art style is still appealing after all these years. The coolest visual addition I saw was, surprisingly, Navi. The little fairy is almost always the closest thing to you because of the 3D. It's nothing spectacular, but it looks very cool, offering another layer of immersion.

The controls are fine, as you can move Link on the Circle Pad, and use the sword, two items, and roll on the face buttons. Everything else is easily accessible on the touch screen. An annoying aspect of the face lift is that whenever you L-target an enemy, the text "Navi" flashes on the bottom of the top screen. As if the little bitch wasn't annoying enough, now she crowds the beautiful 3D screen.
One of the neatest things about the controls is that you can tilt the system to aim the slingshot or look around. It's kind of a throwaway addition, though, especially since controlling with the Circle Pad is so much better in gameplay.

As for the game content, I could probably sleep through Kokiri Forest and the Deku Tree. While I'm excited for this game, I'm not really looking forward to replaying an area I've played ad nauseum. However, if the rest of the game looks as nice and controls as well as this section, I can't wait to replay this N64 classic.
There was no given release date for Ocarina of Time 3D, but from the wording in Nintendo's recent 3DS press release, we might not be playing this game until summer 2011. Of course, until the 3DS launch line-up is actually detailed, we'll be left hanging.
2 Gameplay videos below: