[Update: Fri 24th Sep, 2021 00:15 BST]:
Well, who could have guessed: there's a new Kirby game in the works, and it's called Kirby and the Forgotten Land. It's a 3D open world game set in a post-apocalyptic city, with Super Mario Odyssey-meets-The Last of Us vibes.
[Original: Thu 23rd Sep, 2021 17:10 BST]:
Just a few hours ahead of the Nintendo Direct and we're already getting news trickling in, thanks to what was perhaps an accidental upload of a new Kirby game onto Nintendo's Japanese "upcoming releases" page.
The page has already been taken down, of course, although it may well work again after the Direct, but we can still see the game on the release schedule, where it's slated for Spring 2022:
According to our trusty Google Translate, the name translates to "Kirby Discovery of the Stars", or "Kirby's Dream Land Discovery". Looks like it'll also be getting a physical version, assuming that's what "package version" means.
We won't have long to wait to find out more, as the Nintendo Direct airs tonight at 6pm Eastern, 11pm BST. Also, as our resident video chap Jon Cartwright pointed out, it doesn't half look like Kirby's gone to Nier Automata.