They either removed patterns from a lot of the textures (water, grass, dirt, etc) or they havent fully put them in yet. The look is nice in HD but it needs more character and not so much emphasis on being realistic. It makes other stylized elements look "cartoony" in comparison - the flowers, as an example, seem out of place next to the more finely detailed wild grasses and weeds.
Other than the designs we saw in the trailer and the treehouse, my only other concern is what's been mentioned or hinted at a couple times now, is the focus on customization and how this feels a bit more like a spin-off than the next generation game. And map size, lol.
But, as we've all been saying thus far, we've got 9 months to see what they come up with ~
Yeah I noticed the gameplay had more of a softer look than what we've preciously seen. However, the initial new leaf trailer was a little different from our final version, so they might add or tweak textures for the release. I'm also guessing that the more minimalistic style is to make up for the fact that we can now place MANY more models in the actual town than before, with furnitures and whatnot. Because of that, they may have gone with a more simplistic approach in order for all models to work with the changing of seasons/weather conditions etc. Although we still haven't gotten a confirmation on how many models can actually be placed on the floor (eg. we've seen the difference between "place item" and "drop item") The stylisation/graphic quality of the game kinda bugged me in the trailer but it grew on me when I watched the treehouse gameplay.
I LOVE how simple the time stamp and map looks when it's toggled on screen when you're idle. There was something about the time stamp in new leaf that really bugged me, but NH's version looks really sleek and beautiful. Now we just gotta wait if Nintendo listened to fan's requests for control over villager house placement, etc. Those little things will really make a big difference to the fans.