Alien Covenant is a sequel to Prometheus. It is also the first of two prequel stories which will lead into the events of 1979s Alien. No pressure so...
Director Ridley Scott is back to help bridge that gap, with the plot continuing a few decades after the event of Prometheus and focussing on a new crew as well as the return of Michael Fassbender's David. We're willing to give the franchise at least one more shot - Prometheus had its issues but had its moments and the series hasn't been too overabused with needless sequels.
The casting for the new film is ongoing but the latest potential addition is an interesting one, The Wrap reports that Danny McBride could be in line for a role. The comedy actor is best known for roles in the likes of Eastbound and Down and Tropic Thunder, so it would be strange to see him cropping up in such serious fare. That said, there's a lot of skill required to make people laugh, and many comedians have successfully made the transition to drama.
Apparently the opportunity came about when Scott and McBride met and bonded over a shared love of old movies, which is a strange enough story to be true. This casting isn't confirmed just yet but expect official word pretty soon as Covenant is set to start shooting in April for a October 2017 release.