Pokemon Databaseさんのイラストまとめ

Official artwork and screenshot of Sirfetch'd. It evolves from Farfetch'd in the Galar region "after experiencing many battles".

Official art of Polteageist and Cramorant:

Artwork of the new Pokemon revealed, Obstagoon (Linoone's evolution), Morpeko Full Belly Mode and Morpeko Hangry Mode!
#PokemonSwordShield

Artwork of the new Galarian Forms revealed, Weezing, Zigzagoon, and Linoone!
#PokemonSwordShield

And here's the official artwork of Gigantamax Alcremie, Drednaw, and Corviknight!

Official artwork of Alcremie, Yamper, Rolycoly and Duraludon

Pointless fact: Corviknight is listed as Flying/Steel type, which makes it only the 4th Pokemon to have Flying as its first type, after Tornadus, Noibat and Noivern.

And another titbit not mentioned in the trailer: your Pokédex in the game is a Rotom that's taken over a smartphone!

And here's Corviknight, Zacian and Zamazenda:

Adding official art in a thread to avoid spamming y'all :)
Here's Drednaw, Gossifleur, Eldigoss and Wooloo: