Details are a bit scant regarding this new game (unless you count videos featuring lots of Irish landscape as details), but John Romero and Adrian Carmack are working together on a new first-person shooter.
Carmack (no relation to John, despite their prior working history), also worked on FPS titles like the original DOOM and Quake. Under the name Night Work Games, the pair of them (and some other employees, no doubt), will be fully announcing the project on 25 April. Which, yes, makes this a bit of an announcement-announcement, annoyingly.
Still, you have to hand it to John Romero, he really knows how to stand on a rock in a hooded jacket. The handing over of a mouse and keyboard pretty much confirms, if there were any doubt, that this game will be PC-bound.