Great

It looks pretty cool.

Even though this was only a brief peek at the end product, it still was enough to wet your apetite and give you some ideas of what you are getting yourself into with this future book. A teaser of sorts and I would love to check out either a finished product or maybe a playtest version to get a more detailed feel for the finished product. A nice start. Now let's see more.

I like it. The PDF has useful charts

Overall, the preview shows a large degree of care and understanding of world building. It provides an excellent range of tables to help generate a region, country, continent, or whole world in which to adventure.
Having been doing this sort of work for a very long time I was pleasantly surprised by the level of detail included as well as the well-thought out process for guiding the development.
My only concern, and it is addressed in the instructional texts, is the reliance in random dice rolls to structure the creation. It is wholly possible to create an "hopeless monster" of a setting if the random die rolls are not properly vetted. And that takes both experience and an eye for impossibilities. Even a fantasy-based world needs a certain level of consistency for players to have a good experience and feel like they are in a real world.
I think the full Wondrous Worlds book will allow just about anyone to achieve that end.