A job listing at Gears of War developer Epic Games has revealed that the company is looking for staff to work on "an unannounced competitive online action game". Epic is looking to recruit a Senior Systems Designer with "a passion for building and/or playing Shooters, MMO’s, RPG’s, or RTS games", hinting at a project similar to Ubisoft's groundbreaking Tom Clancy's The Division.
The job ad gives clues about what Epic is planning for this new game, stating that: "One of the teams is working on an unannounced competitive online action game that includes player progression, heavy itemization, and a dynamic economy; the other is for Fortnite".
It's very possible that this unannounced project is a new Gears of War game. Given the popularity of the series on Xbox 360, it seems unlikely that Microsoft and Epic would simply discontinue the franchise, especially with next-gen just on the horizon. Expanding the series into a online MMO shooter with 'player progression' and 'heavy itemization' would make perfect sense for the Gears of War series: however, it's pure speculation at the moment, and Epic is yet to comment on the job listing.
Other Gears of War related rumours suggest that the next trilogy will focus on the Pendulum Wars (and that GoW Judgment studio People Can Fly is working on it), although these whispers have been circulating since before the announcement of Judgment, which acted as a prequel to the main Gears trilogy.