OnceLost Games say they're creating what they believe will be "a new open-world fantasy RPG where choice, consequence, scope and role-playing will be experienced like never before in a realistically-scaled open world in a new class of game: The Grand RPG.".
Alongside the teaser trailer, OnceLost Games have unveiled a Steam store page for The Wayward Realms, which gives some extra details on their ambitions.
This is the first major push to reveal The Wayward Realms, but OnceLost have done quite a bit of kicking ideas and concepts around on Twitter already
Their work on Daggerfall is clearly a big inspiration for the scale that OnceLost are hoping to achieve in The Wayward Realms, which they talk about often
OnceLost Games caution that the reveal of their store page "does not mean that the game is coming out soon," and is more a way to start building a following