My feelings with all informations we have for now:
-Lycanroc New form (meh)
-Necrozma new forms (Solgaleo one will be broken in strat but both are meh)
-UB Burst and Assembly (cool designs, types disappointing, only the first will be used in strat)
-UB Adhesive ()
-New Z-move for Kommo-oh (broken), Mimikyu (meh), Lycanroc (interesting) and Necrozma (meh), Mimikyu (not confirmed)
-Ultra Dimension travels (look fun but not convinced for the moment)
-Rotom Dex O-Powers ()
-Mantine Surf (in a Pokemon game? Seriously? At least Pikachu mini-game was a bonus feature not a main one)
-Return of Festival Plaza and Battle Tree ()
-Alola Photo Club (useless)
-Valley of Pikachu (come on)
-New Pikachu hat (meh)
-New Move: Mind Blow (risky in strat)
-New Story: The most interesting thing but do we really play Pokemon for the story?
-Island Trial changes (annoying sorry)
-Rockruff event (great) but only the one from Ultra Sun will be really used in strat (so disappointing).
Results:
For the first time I'll essentially wait a Pokemon game for its story.
Some new features looks great or at least interesting (Lycanroc Z-Move, Necrozma-Solgaleo, UB Burst and Assembly designs) but most of them are meh when they are not useless or disappointing (return of Festival Plaza, Battle Tree, Alola Photo Club, Mantine Surf, Valley of Pikachu, Rotom Dex O-Powers ...).
In fact I think it's more a communication problem than a lack of work of GF. They communicate too late, on bad things, bad tempo.
Really hope they'll correct that for Pokemon Switch.