I literally like everything about this except Ash's design. Like, bruh. What? How? Why is he so round? So curvy? His hair is just... and his cheekbolts! XY finally fixed that. Man...
At least everyone else looks good. Well, maybe not Pikachu, and I'm not sure about other Pokemon, but the human characters look great. And the animation being more cartoony is a good thing, too.
The inclusion of Team Skull grunts in the preview is definitely a good thing. Sure, it has the goofy PokeRide shenanigans and Z-Move poses and Team Rocket, but if it manages to tell a story even as half as serious as the Team Flare arc, then I'm in for the long run. I'm sure the Ultra Beasts and the Aether Foundation will appear eventually (personally looking forward to Guzma's first appearance and Gladion battling someone using Type: Null).
On top of that, just think about all the stuff they can do now in an episode: Pyukumuku tossing, a beach episode, a festival episode, a mini-vacation arc, school trip episodes, fishing, PokeRide stuff like races, etc. on top of the regular battling and stuff. We might even still get Trial Challenge episodes, and battles with Totem Pokemon (i.e. Ash and Mallow get lost in the Lush Jungle so go searching for ingredients for Mallow to cook, accidentally run into a Totem Lurantis, they battle, Mallow's Bounsweet evolves or something).
Really glad the main cast is larger than usual, too, and it'll be fun to see the Trial Captains and Lillie interact with each other and Ash. Of course, it could just turn out to be the worst series so far, but I'm hopeful.