Latest leaked Windows 10 build reveals support for recognizing hand gestures, 3D stereo headsets and more

The latest build 9901 of Windows 10 which has just leaked has revealed many new features, particularly if one looks at the APIs which have been added.
The Walking Cat did just that, and posted the diff of Build 9879 and 9901 on pastebin.
A large number of new APIs have been added, including numerous phone ones, but of particular interest is a whole new class called Windows.Human.
This seems to be dealing with new user interfaces using voice, gestures, poses and even face tracking.
It appears, from looking at the APIs, that users will be able to zoom and scroll using hand gestures, without touching the screen.

Windows 10 will also recognize and track your face and facial expressions, opening up the possibility of deleting an email with a raised eye brow.
Also new is support for a Stereo Head Mounted Display, which should open up plug and play support for devices like the Oculus Rift and on Windows Phone possible a version of Google Cardboard.
Lastly of note is references to Casting for photos, music and video, by Windows Media Player, which may mean that Miracast support will be much more deeply integrated in Windows 10.
More more can be uncovered by trawling through the Pastebin archive here.