It has been confirmed that Blizzard is indeed developing Diablo III for the Xbox One.
However, it is not yet sure if it will be released, as that decision will be up to Microsoft. Confirming an Xbox One version, Lead producer Alex Mayberry stated to VideoGamer:
I don’t know where we are with Microsoft right now so I can’t really comment on what that contract looks like, The point is we are developing for Xbox [One] and PS4 simultaneously. We hit those major platforms and then our goal as a development team is to make them run.
We have that pipeline worked out… And then Blizzard and Microsoft can work out whatever they work out.
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