Announced during the Xbox E3 2017 Briefing, Original Xbox games are going to begin being added to the Xbox One backward compatibility program later this year (2017). No release date has been announced as to when this will kick-off, but we do know that the first game that will be coming from the original's library is Crimson Skies: High Road to Revenge.
Coming from Phil Spencer during the Xbox Briefing:
"Our team of engineers are working hard to bring some of your favourite original xbox games to today's Xbox One library, including a fan favourite that I'm asked about often by the community: Crimson Skies - and it looks great. And like the Xbox 360 games, OG games will look better, and play better across the Xbox One family. We'll have more to share about this program when it launches later, this year."
Since the on-stage announcement Phil has gone on to expand on a few details regarding the original Xbox backward compatibility program, talking about how difficult it's been to get some of the classic games due to rights, and more.
Here is what Mr. Spencer had to say on the topic when talking with Gamespot:
"So we only showed Crimson. Crimson's one of my favourites from the original Xbox - I thought it actually looked really good, it was one of the things, putting it on a 4k screen, I was a little worried about how some of the old games would look.
Discs work. So if you've got your disc, when the game's been enabled, you'll be able to put a disc in, so just like 360 it's not for every game. It'll be a smaller number of games than it is on 360, mainly for rights reasons though - some of those companies, we go back and the companies that published those don't exist anymore, and we do have to get rights clearance and other things, but we'll talk more about what's coming, it's coming this year, and I'm excited about the list."
Original Xbox Classics Backward Compatibility will launch sometime in Q3/Q4 2017, starting with Crimson Skies: High Road to Revenge. No other titles have been announced at this time.