343 just revealed the new Halo remaster collection, Halo: The Master Chief Collection.
Major Clarke was revealed as a new Halo character (see the Halo 5: Guardians art work), and 343 will be retelling Chief's "legendary tale" from November 11. We'll be able to play the entire Master Chief saga on Xbox One.
With Halo: The Master Chief Collection, all content will be unlocked from the start, that means custom playlists, and 100 maps running at 1080p. There's also going to be a 4,000 gamerscore.
It's the ten year anniversary of Halo 2, which is getting "the full anniversary treatment". It'll contain the original multiplayer of that game, exactly as it shipped a decade ago.
Dan Ayoub and Bonnie Ross revealed the details during Microsoft's press conference, and once they'd finished talk of the remaster, it was confirmed that Halo 5: Guardians would be going into beta on Xbox One during December, and purchasing the Master Chief Collection would give you access.