This change to the teaser site would seem to strongly hint that any games that are made with DirectX 12 will work seamlessly with Microsoft's latest home console.
And now, that hint has turned to reality as the Xbox One has been confirmed by Microsoft to support DirectX 12!
One of the questions asked when this reveal was announced is that can the Xbox One handle DX12? One of the issues of Xbox One is that it can't handle rendering games at 1080p compared to the PS4. And now it seems that DirectX12 would actually help the Xbox One in rendering games at 1080p. When Phil Spencer was asked about DirectX 12 and the resolution issue, he simply said. Which hints at something major will be announced come GDC 2014.
DirectX 12 will be the subject of a presentation at the 2014 Game Developers Conference in San Francisco on March 20th. However, we may have to wait until at least spring 2015, the projected launch timeframe for Windows 9, before DirectX 12 becomes available.