DirectX 12 games such as Fable Legends for PC will be able to use the programming interface to allow cross-platform play between Windows 10 PC and Xbox One owners.
DirectX 12 cuts the power consumption in half when compared to DirectX 11, allowing more mobile devices to run "high-end" mobile games. For the PC users, you won't have to buy expensive PSU units for running DirectX 12 games.
Hope for the best! 
Source: IGN