Metroid Prime 4 is coming. No, really - it was just confirmed during Nintendo's E3 presentation.
Nothing was shown beyond a logo, with statement saying it was currently in development for Nintendo Switch.
It has been confirmed that Retro Studios isn't developing this new game. Producer Kensuke Tanabe has stated that he's leading “a talented new development team." Tanabe acted as producer on the first three Prime games.
So if Retro isn't working on Metroid Prime 4, what is it working on? The studio has been silent since the launch of Donkey Kong Country: Tropical Freeze.