Apparently rumors of the demise of Irrational Games have been greatly exaggerated, even if they were based on an official announcement from the studio founded by Ken Levine saying they were "winding down" operations. It seems they are getting wound up again, as their Careers at Irrational page now lists two open positions (thanks Lazygamer), one for an IT manager, and the other for a senior programmer with a focus on "AI & Gameplay." This latter listing has word that "Unreal Engine 3 and 4 experiences highly desirable," and features the following overview if you want to comb for hints about what's up:

Irrational Games is currently looking for a Senior Programmer that is equally experienced in architecting and implementing AI and Gameplay systems. This position will work directly with the Lead Programmer, along with the Animation, Art and Design teams to create fun and interesting AI opponents and gameplay elements for our next title. This position will also be responsible for additional core responsibilities including, but not limited to general gameplay features, tools, engine technology, and build systems.