See my edit.
So, I didn't expect the final evolution of the starters.
Especially not Decidueye's Grass/Ghost typing. Spirit Shackle seems like a good move, causing damage while trapping foes. It may be a little awkward to use considering that the opponent you want to trap can just switch before the move hits. Still seems good though.
Incineroar is a dumb name and he shall be known as Tigreatest instead. Fire/Dark as about half of people suggested, which is a neat type. It seems to have a good personality. Darkest Lariat is a cool name, but the animation kinda looks like it is in its t-pose and spinning forward. Renamed and retyped Chip Away. Meh.
Primarina is a pretty name, and so is that Water/Fairy typing. Looks cute. The same can't be said for Sparkling Aria. It seems like a niche Guts/Flame Orb check. Maybe if it does double damage against burned foes like with Smelling Salts and Wake-Up Slap it can be sorta useful with Scald. Maybe.
Tapu Lele is cute, and it has Psychic Surge for Psychic Terrain which either removes priority from moves or stops priority moves in general, I don't remember.
Tapu Bulu is Grass/Fairy which is a bit unexpected coming from Ula'ula island (is the first time we've officially seen this island's name?) and the home of Baile style Oricorio (assumingly). There were theories that the remaining Tapu were the same type as that island's Oricorio, but I guess not. Grassy Surge sets up Grassy Terrain which is not new. The effects seem nice enough though. Nice Horn Leech.
Tapu Fini is Water/Fairy which is unexpected yadda yadda repeating the previous part. Is the name Poni island actually new? Kinda lame it just gets Misty Surge and so Misty Terrain instead of a new water one, but whatever. She's cute.
The Tapus' Z-Move is interesting. Apparently it's pretty much Super Duper Fang, shaving off 75% of a foe's HP. Disappointing that the body is always yellow.
Cosmog is adorable. Psychic typing. We knew that it was Lillie's pokemon from those articles like Polygon's where they spoiled it. Totally just a normal pokemon and not special in anyway.
Good ol' Garfielf. Fur Coat is an interesting ability. Hopefully it has better defense and reliable recovery *crosses fingers for Slack Off* to be able to use it, or it will just keep Technician for rad Bites.
New league seems hype.
Battle Tree, aka PWTree(?), seems super hype. Better post game content here hopefully than XY. Going by the Japanese trailer you fight normal trainers and then eventually special trainers, like a remixed Battle Tower or the Orre Colosseum from XD. New model for Cynthia is neat, but Wally's model is the same I think. Older Red and Blue is super hype. Special note how in the trailer Blue addresses you as a fellow Champ. This is post Alolan league then?
Looking at moves in the Battle Tree in the Japanese trailer, Vikavolt learns either Razor Wind or Air Cutter (don't know which that animation is), Drampa learns Flamethrower(?), and Lurantis learns Solarbeam along with its Solar Blade.
Can safely I did not expect most stuff from this trailer. Very nice trailer.
And now for my favorite part.
[spoiler=Stats]Assuming neutral natures and no EVs.
Alolan Raticate has higher HP than normal Raticate. Normal Raticate reaches 178 HP at level 70 with 31 IVs. Alolan Raticate has 193. This puts its base HP anywhere from 66 with 30 IVs (65 is 192 and 66 with 31 is 194) to 81 with 0 IVs. I can narrow it down further however, as in the Japanese trailer it was seen at level 41 with 121 HP. That range is base 70 with 31 IVs to base 86 with 0 IVs. We know it can't be 86 though, so the closer range of Alolan Raticate's base HP is from 70 to 81.
Zygarde 10% has 177 HP at level 70. This is much less than normal Zygarde who would have 252 at that level. I predict Zygarde 10% has 54 base HP, as that fits with the video, and that is half Zygarde 50%'s base HP value.
Alolan Exeggutor has 234 HP at level 70, which is what normal Exeggutor would have at that same level with 31 IVs. Alolan Exeggutor likely has the same base HP as normal Exeggutor, so 95.
It's hard to read Incineroar's HP in the Japanese trailer, as I think it's been smudged a bit. It looks like 160 HP at level 50, which puts it anywhere from base 85 with 31 IVs to base 100 with 0 IVs.
Tapu Lele has 172 HP at level 60. Base HP is somewhere from base 70 with 31 IVs to base 85 with 0 IVs.
Tapu Bulu is the same HP wise. Judging on how it did 117 damage to a level 58 Tauros with STAB Wood Hammer (Wood Hammer does 1/3 of damage dealt as knockback, and Tapu Bulu took 39 damage), Tapu Bulu has somewhere from 120 to 140 Attack (damage range is a bit of an annoyance). I don't want to go through all of the process of shifting between Tauros' Defense and HP IVs and Tapu Bulu's Attack IVs, so I'm just gonna say it probably has around 130 Attack, give or take 10 points.
Tapu Fini is the same as the others HP wise. Technically Tapu Fini has at least 70 Special Attack since it oneshot that level 57 Magmar with STAB Hydro Pump, so it is hard to say how much power it has. Probably at least 100 Special Attack.
Level 50 Mudsdale had 178 HP. Base 103 HP with 31 IVs to base 118 with 0 IVs. Doesn't have as much HP as I thought it would.
Alolan Raichu's HP was 126 at level 50. That puts it from base 51 with 31 IVs to base 66 with 0 IVs.