Well it looks like the rumour of the Halo series (1-4) coming back as an HD remake set turned out to be true. All four games will be contained on one disc, with the focus of multiplayer being on Halo 2 as its anniversary is coming up this year. All of the games will be running at 1080p/60Hz so gameplay wise it will be one of the smoothest Halo experiences ever made (since PC).
Halo Collection will be coming to the Xbox One later this year on November 11th from 343-Studios.