343 Industries, the studio that brought us Halo 4, is currently working on both the next entry in the Halo series for Xbox One, as well as a television series set in the same sci-fi Spartan-filled universe. However, it doesn't end there, as the developer has confirmed it is also working on other projects that have yet to be formally announced.
Over on Halo Waypoint, 343i posted the following statement regarding its development plans:
What is looming on the horizon for the studio is both exciting and daunting. We’re working on projects that you know about (the TV show and Halo Xbox One) and others that you don’t (insert absolutely zero clues here). Our team has blossomed from a few dozen to a few hundred, and it continues to grow at a healthy pace as new people are hired to make sure every team has more than enough resources to do their job, and do it well.
Are you hoping 343i is working on something entirely removed from Halo, or do you think the studio should keep its efforts focused within the franchise? You know... one of those new "projects" could very well be the long-awaited HD remake of Halo 2. At least, I hope it is.