A few days ago on twitter, Mike Ybarra, engineering lead at Microsoft, said that a new Xbox update will be coming in the near future; or as he simply put it, 'soon.' The tweet didn't do much else other than confirm the existence of the update, and that it would make its way to preview consoles first, as with all updates.
A little while back, the Xbox One Anniversary update was announced, and it was slated for an early June release for preview testers. There is nothing confirming that this update will be the Anniversary Update, but we think it's quite likely. The Anniversary Update will be coming to PC too, and will contain a myriad of features, including the ability to turn your Xbox One into a development kit. We also expect Microsoft will want to launch it proper during E3 if it is possible.