I think you can do something similar to this in both Wind Waker and Twilight Princess. If you L/Z-target without having any enemy around to actually target with the bow, you are pretty much able to walk around freely like this--well, minus the first-person part of course. I'm pretty sure that's what the player of the demo was doing, so I think Nintendo just gave the first-person shooter-esque perspective to the bow when you're targeting enemies from a distance since so many gamers nowadays are into it, so it will be an easy change to adapt to for the Zelda series (sadly, I am not one of those gamers).
If I were to guess, you'd probably still have the typical bow & arrow screen to manually aim without targeting--and probably won't be in first-person perspective. But... who knows until two more months when it is released.