It's called "Ronja, The Robber's Daughter," it's based on a book by Astrid Lindgren (of "Pippi Longstocking" fame), it's directed by Hayao Miyazaki's son, Gorô, and I don't really know what to think about it.
The themes/settings feel Ghibli-esque to me (though I wasn't quite sure 'til the magic-whimsy showed up around a minute through the trailer), but the obviously CGI character animation feels like a stark (and somewhat unwelcome) departure from their usual aesthetic. I suspect that's because the primary animation is being done by Polygon Pictures, not Ghibli.
The 26-episode dual-season is getting its US release through Amazon Prime on January 27th. (It was first released in Japan in 2014, so I'm not quite sure what "Amazon Original" means.) I'll definitely give it a try, though the CGI-boxy-ness gives me definite (infinite?) pause.
Presented by Studio Ghibli. The daughter of a professional robber, Ronja realizes the complicated nature of her father’s profession when she befriends Birk, the child of a rival tribe. She struggles to balance this friendship with her family relationship but comes to understand, how differences can be overcome with the help of love and understanding.