Surely we all had some kind of disappointment, but let's focus a bit on met expectations, shall we?
Not trying to be an apologist or shill, just trying to focus a bit on what looks cool so far.

>Cold Region
Not only does it have a big portion of snow on the map, it also seems to be predominantly cold. Even on the south, presumably hotter, we can see the MC's house has a heater, as marked in pic related.
Nice change after 3 games in a row on tropical environments (4 if you count Kanto, which is sunny all the time).
>Vibrant and diverse world
May not be the BOTW some expected, but it sure looks colorful and beautiful. It seems we'll get some diversity in areas too, like a foggy forest, countryside, industrial/steampunkish cities, and lake areas we haven't got since Sinnoh, i guess.
>Older MCs
They seem at least 14, also a nice change of pace after ORAS, (U)SM and Kanto having us play as toddlers.
>More traditional, less GO
I kind of wanted to see overworld mons, but at least we got wild battles and regular catching back. If anything, it's a good sign that they are raising boundaries between the core games and (Let's) Go.

What else caught you attention positively on the trailer?