Gearbox, the studio responsible for Borderlands and Battleborn, is working on a 1v1 shooter which is also, somehow, a collectible card game. The "top-secret" project, dubbed for the time being Project 1v1, was revealed via this official website, rendering it immediately no longer top secret.
According to the site, it "combines the action of fast-paced 1v1 first-person combat with the metagame strategy of a collectible card game". I've personally only ever done those things separately, and generally if I'm in the mood for shooting things in the face, I'll stay well clear of card games. But I'm still very curious to see what this is all about.
There's a closed technical test scheduled to happen this summer (winter in Australia), which can currently be signed up for. It'll be North American centric, with international players warned that they might get "decreased performance". Three modes will feature including ranked, challenge and arena.
And that's all we've got to go on at the moment. Gearbox is also working on Borderlands 3, though we have no word on how close a release is for that, nor whether Project 1v1 will affect it (I doubt it).