It has been understood for a while that Microsoft will release two Xbox consoles as part of its next generation refresh (Xbox Two?), now we have the internal codenames.
The latter follows Microsoft's general reptile-based naming convention, with Durango and Scorpio used for the original Xbox One and Xbox One X respectively.
Both fall under the Project Scarlett name bandied around previously.
The Xbox Lockheart will be a direct replacement for the Xbox One S, it is said. It will be the cheaper of the two and feature similar hardware to the current Xbox One X - albeit with a few enhancements.
The more powerful Xbox Anaconda will be the flagship console, with full 4K 60fps gaming without compromise. Both machines are said to be arriving in 2020. We might even see Microsoft announced them during 2019's E3 in June - something that will go unanswered as PlayStation will not be attending this time.
These will be in addition to a machine running the new Xbox cloud gaming platform, Project xCloud. Rumours are that a modified Xbox One S with no disc drive will be announced soon and released in 2019 as a stop gap. Microsoft is even said to be considering offering gamers with a disc library the option to convert them to digital copies.
Whether this will be for a small fee is currently unclear.