Halo 5: Guardians

Not to be confused with Halo 5, the game announced together with Halo: CEA, Halo 4 and Halo 6 during E3 2011.

Halo (Xbox One) is an upcoming Halo game introduced during Microsoft's E3 2013 presentation as the second chapter in the John-117 storyline of the Reclaimer Saga and the sequel to Halo 4.

Xbox One Reveal
Halo (Xbox One) was confirmed to be in development for the Xbox One during the Xbox One Reveal event on May 21, 2013.

E3 2013
The Halo (Xbox One) E3 2013 teaser trailer opens in a large desert plain with a cloaked figure traveling across the sand hills. As the figure walks, the sands in front of him begin to open up and give rise to an unknown bird-like Forerunner Construct. The cloaked figure holds out his hand and opens it, revealing an AI data crystal chip. The construct opens its "wings" and releases a large pulse, which knocks off the hood off of the cloaked figure, revealing him as John-117. The screen fades to black, and the text "Halo," "2014: Your Journey Begins On Xbox One," and "343 Industries" appear.

"There was no ambiguity in not putting a number after the game. For me, what we showed wasn’t the game. Nobody should be confused on that. I didn’t really want to try to show something that was clearly a thought piece by the studio around where Master Chief is in his journey, and then drop the name after it and be somewhat disingenuous about that being the game. But I did want Bonnie [Ross] to come out and say 'First-person shooter. Master Chief.' Because they'll get the questions: 'Hey, is this ODST? What are you guys doing?' Bonnie [Ross] comes out and reaffirms that 343 is building this game. It’s Master Chief. It’s a first-person shooter at 60 frames per second. It’s coming in 2014."

- Phil Spencer, regarding the teaser trailer

Trivia

 * According to Microsoft Studios' Phil Spencer, "the upcoming Halo game is a genuine entry in the sci-fi franchise. The series is no longer a trilogy, but now a saga."
 * This will be the first main Halo game to be released on the Xbox One.