So far, the only information we have about Doom: The Dark Ages is the paltry trailer shown off earlier last year. More information about the title should ideally emerge at Xbox's upcoming Developer Direct on January 23. Meanwhile, an eagle-eyed Resetera user stumbled upon some spicy information about the upcoming Doom game.
A now-deleted post from a French publication says Doom: The Dark Ages will launch on May 15, 2015. That's a little over five years after Doom Eternal dropped, and sounds like a plausible launch time. Either way, we only have to wait for a day more to find out for sure. One can reasonably assume Doom: The Dark Ages will use some form of id Tech 7, the engine powering Indiana Jones and the Great Circle.
Whether it will have the latter's ray tracing features baked in remains to be seen, but the Doom: The Dark Ages will certainly demand some beefy hardware, especially at higher resolutions. Fortunately, new GPUs from Nvidia and AMD should be out and about by then. That said, Doom Eternal was one of the best optimized games of its time and there's no reason why its successor will not follow suit.