Developer id Software's pedigree and legacy dates back to the 90s, with the release of many fan-favorite franchises that are still supported to this day. This is evident with the developer's flagship Doom franchise, with modern critically-acclaimed entries like Doom Eternal showing how the developers at id Software can still deliver feature-rich first-person shooter experiences.
While recent Wolfenstein games haven't been developed by id Software, the primary developer being MachineGames, the Quake series has seen a bit of a resurgence thanks to the studio. This includes a surprise remaster of the first Quake game on several platforms. This remaster comes complete with upgraded visuals, new content, and more. While it's not known if the next game from the developer will be another Quake, recent job postings from Zenimax, id Software's parent company, indicates a new project is at least in the works.
The job posting notes that id Software is searching for an experienced Senior UI Programmer, which is a position that works with the artists and gameplay designers to create player-friendly user interface elements. The position is stated to be for an unannounced video game project, though considering id Software's library, it's very likely to be another FPS game. This is supported by previous job postings from Zenimax that have hinted it is being developed for "long-running iconic action FPS," for example. This can include either another Doom entry, or even a rebooted Quake game.
Other than that, not much is known about this game for the time being. The one thing of note that can be gleamed from this id Software job listing is that it will be aiming for the PC and next-generation consoles. Based on this statement, it's likely that this means the game won't be supported on the past console generation, so it will likely be skipping PS4 and Xbox One. Fans can expect that this game will take advantage of the new console hardware, which can support visual enhancement features such as ray tracing.
With id Software working on this new, albeit unannounced project, fans have something to look forward to. A new Doom, Quake, or even a completely different FPS could be an excellent addition that can be comparable to other entries from id Software's library. However, this is all speculation at this time, so fans should keep their expectations in check until the curtain is unveiled on what this project is.