Update: It's official.
Original story: It's not official (yet), but it definitely looks like Mass Effect 2 and Mass Effect 3 are coming to Xbox One via backwards compatibility. Over on Reddit, user Tunga88 claims to have spied Mass Effect 2 and Mass Effect 3 DLC on the Xbox Games store. What's more, user moneychex points out that if you pop in disc one for either ME2 or ME3, you can install the games to your hard drive.
I gave moneychex's advice a try, and yep, it works. Although the console initially warns that the game isn't backwards compatible, manually selecting it brings up the option to update the game for Xbox One.
I've also gone ahead and verified the appearance of Mass Effect 2 and Mass Effect 3 DLC. Here you can see the option for me to install the Arrival DLC for ME2 on my Xbox One. And you can tell it's not photoshopped because I'm a terrible photographer!
If it hasn't been made official by the time you read this, I expect BioWare and EA will be announcing this feature very soon.
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