Zigfu is still in development, but it's just me now and I'm slow to update new features, I'm still catching and fixing bugs. The ZDK for Unity3D doesn't quite make enough money to work on it full time, but I am seeking to hire support to build new features in a part-time basis. I put up a roadmap of upcoming features, FaceTracking is already a branch in our github:
1.2 FaceTracking
1.3 Update with more of the Kinect 1.5 & 1.6 functionality (joint orientations, bulk pixel registration)
1.4 initial multiple kinect support
1.5 audio/speech
1.6 Some of the new kinect 1.7 SDK features (not sure if they're public yet, but we're on the technical adoption program with MSFT)
1.7 overhaul of event system (want to remove SendMessage in favor of delegate events)
1.8 higher resolution streams
1.9 More Demos Docs and Tutorials
The 2.X release isn't mapped out yet, but will be more about integrating new sensors.