Important: Please Read
This article is about a game that does NOT exist. It shows signs that Quake 5 could be created but there are NO promises that Quake 5 will ever be made.
John Carmack Interview June 2011
Quake 5 is a so far non-existent title and over the many years since Quake 4 and Enemy Territory: Quake Wars, id Software has not handed its fans any indication that there would ever been a new Quake, see this article from 2008. But on June 17th, 2011, John Carmack finally gave fans the little spark of hope they'd been waiting for.
In this article for multiplayerblog, Carmack talks about how much he loved playing the original Quake online in the late 90s and that despite the First Person Shooter genre moving on in the 15 years since Quake, Carmack likes to think a game like Quake could "compete with the military-heavy, gritty realism of today's biggest sellers".
Carmack talks about that doing another "Cthulhu-ish", H.P Lovecraft type game like Quake would be a possibility instead of going back to the Strogg storyline covered in Quake 2 and Quake 4, as he believes that storyline to be finished. id Software is getting tired of the Strogg storyline, and he believes the gamers are too. He even says he was not entirely happy with the direction that Raven took Quake 4 and its lack of inventive game play in multiplayer. Ironically, after creating Quake, he was not that interested in the Single Player campaign that was created. John Carmack and the rest of id Software believed Quake to be a random disappointment due to the mergeance of ideas. He believes Quake only worked due to the revolutionary aspects of the game, such as Multiplayer over the internet or a fully 3d world. Carmack promises a better storyline if Quake 5 were to be made, but with many elements borrowed from the original Quake.
All in all, it appears that Carmack is thinking about the possibility of bringing the original Quake into the 21st Century, going back to its roots and being nothing like modern FPS games such as Killzone, Crysis and Call of Duty. It seems he wants a game just like Quake to compete with those modern games just like it was in 1996.
Of course, there are no promises here, "there's no indication from the interview that id is looking to make Quake 5". At this time, id Software is focused on creating Rage 2 and Doom 4, and have said Quake 5 won't be released any time soon. But after years of hearing nothing, this at least gives Quake fans a bit of hope that perhaps in the future (albeit not the near future), they will be playing a new Quake game that, if Carmack's ideas are anything to go by, could very well be the best Quake since Quake.