Here you guys go. This information is provided from an inside source at Game Informer Magazine. They will be running an article in July that discusses gameplay and functions/details of both games after Nintendo/GameFreak E3 event in June. Expect lots of more details in that as well.

Starters:
> They will evolve at Levels 20 & 40
> Sobble Final Evolution: Water/Ghost
> Scorbunny Final Evolution: Fire/Steel
> Grookey Final Evolution: Grass/Fighting

> Mythical Wolf Pokemon (Based off of English Werewolf Folklore)
> Mythical Dragon/Snake Pokemon (Based off Lochness Monster in Scotland)

> Wolf like Pokemon in the trailer carved into the mountain is supposed to be a Crop Circle regarding
the Mythical Wolf Pokemon. (Southern English Countryside is huge for Crop Circles)

> New Pokemon based off of a Narwhale (Steel/Ice) and a Puffin (Flying/Water)

> Mega Evolution Returns w/ Johto Pokemon. Mega Azumarill is one of the new additions.

> Ride Pokemon Return

> Expect 90+ new Pokemon, including new Galar forms.

> 16 Person Bracket style Pokemon League Championship (Like the World Cup)

> Quests have been added and they will change the way the story line a bit but not the way it ends. They will also change the opponents you face in the Pokemon League Championship.

> Postgame will include the following.
> National Dex
> Battle Frontier (Location to be revealed after postgame starts)
> Safari Zone (Same area as Battle Frontier)
> Legendaries from previous Generations (Version Exclusives)