The next major firmware update for the Xbox One will be made available to Preview members between May and June this year- so as long as you are a part of the Preview Program, you should be able to get a sneak peak at what major additions and changes Microsoft have planned for Xbox ahead of E3.
This was confirmed by Xbox’s Mike Ybarra on Twitter. “Win10 Anniversary Update announced at //build will have key gaming features, so next Xbox system update goes to preview end May/early June,” he said, indicating that it will not be long now before we get the new update- or well, those Xbox One users who are a part of the Preview Program do, anyway.
The Windows 10 Anniversary update is scheduled to add major features to Xbox One, including the universal windows app store and support that will unify the digital app offerings across Windows devices and Xbox.