It’s ironic… These are the creative features I've always wanted. A ‘free-world’ Animal Crossing with the control to customize and move things around. But, unfortunately, with this new creative freedom, it looks like you’re stuck as a Nook employee with no home of your own to build. All this customization and awesome placement options are limited to other villagers homes.
It also looks like you cannot roam around this town going in and out of those cool weather patterns (and it doesn't look like there is any kind of cohesive town interaction where everyone talks with or about each other). In my opinion, they gave us all the freedoms that we wanted and tons of new features (control villagers, free range house placement, place trees and stuff anywhere, decoration, new public places, etc.), but they took away the ownership of the town itself. I guess we cannot have both.
I don’t know why they just couldn't release an ACNL sequel (or update) with these great new features added. I want the same ACNL game, but with creative ‘god-mode’ control – no silly game limitations and quests (or at least make a creative mode optional). With this new release, they tease with the options we always wanted, but in a very different AC world where you are just a designer, but cannot live in or appreciate the town that you've created.
I love just walking around my pristine town aimlessly as I interact with other villagers and walking on the beach – it’s very relaxing. In HHD, it looks like there is a lot of scene switching as you're limited to popping in and out of houses as you work on them and it looks like you can only roam around the upper portion of the main street area (or whatever they are calling it).
Hopefully I am wrong, but this is what I've gathered from watching this video.