My guess is that he'll be milling about the Plateau and you can ask him questions or guidance if needed.  This is the demo segment and for that demo area I think he serves as a sort of hands-off guide.  He won't follow you or offer advice without request but you will be able to go to him if you wish.  That's my guess.  And in that scene he was showing the player a way to get across that canyon.  Or actually...no wait wait. I think I know who that is.  He's the lumberjack that lives in that small cabin!  Near the gorge there's a cabin where you get the Axe.  In the demo, it is uninhabited but remember, they disabled nearly all NPCs for the demo.  But in the full game, a lumberjack or hunter lives there.  He probably lends or sells or gives you the Axe.

timelapse shot

I think Nuvendil has the right idea; it's either the old man guiding you through things you can do, or it's the actual lumber miller man living nearby. As for the old man, I think there's a resemblance between him and the king in WW, so that might be the king? Or a sage?

This game seriously gives me chills.

It has begun:

https://youtu.be/BiKbXVOe6-E

Twilight Princess is probably the most dramatic for me, but I still feel that of all of them, Ocarina felt the most like an epic adventure. Not quite sure why, I think it's a combination of the soundtrack and the covering of multiple time periods.

Time travel definitely elevated what would have been a rather mundane plot.  For me,  I just love TP's dramatic flourishes in key moments.  And in full blown cuts cents characters in TP are surprisingly expressive.   Though story execution is most excellent in Skyward Sword.

TP and SS do both have more memorable and expressive characters. What makes Ocarina the most epic for me is less about the details of the plot and more about the "feel" of it. It really did feel like a spared-no-expense epic fantasy tale spanning decades with an impeccable balance of dramatic darkness and colourful quirkiness.

I've already had a little talk with Veknoid about this, but I guess I'll say what I think here in the thread as well. I'll probably ramble on a bit though, so feel free to skip to the last sentence if things get boring.

What we saw of Breath of the Wild was amazing. I probably haven't been this excited about a new Zelda game, or maybe even for any game, since Twilight Princess. Not for Phantom Hourglass, nor for Spirit Tracks, nor for Skyward Sword, nor for A Link Between Worlds and definitely not for Triforce Heroes. I liked those sure, one more than the other, but with this new game I feel that we'll finally have something that will have a great impact again. The massive world, the tons of places to explore, the mystery of the story, the interaction between everything and of course, a feeling of adventure not seen since the original Zelda game.

For reference, I always rank the Zelda games like so. I already posted such a list before, excluding Triforce Heroes I believe, but humour me here, I'll take any excuse to post arbitrary lists:

1. Ocarina of Time > 2. Link's Awakening > 3. Twilight Princess > 4. Majora's Mask > 5. A Link to the Past > 6. Skyward Sword > 7. Legend of Zelda NES > 8. A Link Between Worlds > 9. The Wind Waker > 10. Spirit Tracks > 11. Oracle of Ages > 12. Oracle of Seasons > 13. Adventure of Link > 14. Phantom Hourglass > 15. The Minish Cap > 16. Four Swords > 17. Triforce Heroes

The only one I never played is Four Swords Adventures on Gamecube, but I assume it would be between TMC and FS. Plus, I'm getting to that, some day.

Anyway, Ocarina of Time and Link's Awakening are on mile-high pedestals for me. Those games are basically perfect. I don't really expect Breath of the Wild to realistically beat my liking for those two, but how could it really? Not only are they my #1 and #2 Zelda games, they are also my #1 and #5 favorite games of all-time! As per the list I used in dear Smeags's end-of-the-year threads. Then, there's the all-time classics, Twilight Princess through the original NES The Legend of Zelda. From what we've seen I'd say Breath of the Wild is a serious contender to nestle itself between those top games. I think A Link Between Worlds's days as the #8 are at the very least counted, and Legend of Zelda and Skyward Sword will seriously need to watch their backs. A Link to the Past and Majora's Mask could get a little sweaty for the fear of losing their spots and even Twilight Princess is probably not completely safe.

Long story short, from what we've seen, it could potentially fall into my #3 to #7 spot. Exciting times!

Great catch on the mysterious figure behind the tree in the trailer. Even if it is the Old Man, then they still cut some things for the demo, because he never made an appearance at that spot...

Ah! New list opportunities. All tough questions, but I've been busy brewing answers to these kinds of stats in my head for years now, so I think I can come up with confident winners for me.

• Best Dungeon: Forest Temple, Ocarina of Time
• Best Overworld: Hyrule, Ocarina of Time
• Best Boss: Stallord, Twilight Princess
• Best Mini-Boss: Dark Link, Ocarina of Time
• Best Soundtrack: The Wind Waker
• Best Musical Piece: Hyrule Castle Theme, A Link to the Past
• Most Satisfying Art-Style: Majora's Mask
• Coolest Item: Double Clawshot, Twilight Princess
• Most Fun Mini-Game: Goron Racetrack, Majora's Mask
• Most Engaging Side-Quest: Reunite Anju & Kafei, Majora's Mask
• Best Story: Link's Awakening
• Best Companion: Midna, Twilight Princess
• Most Intimidating Villain: Ganondorf / Ganon, Ocarina of Time
• Best Side Character: Marin, Link's Awakening
• Most Zelda-y Zelda Game: A Link to the Past

EDIT: I could also list the negatives of these by the way lol