See the Unreal 4 engine in action in this trailer for Primal Carnage Genesis.
Faceware Live and Unreal Engine 4
Faceware Live is integrated with Unreal Engine 4, allowing for easy to use real-time markerless facial motion capture.
Dynamic Lighting Gameplay with UE4 and Enlighten using Blueprints
Geomerics have posted a detailed article on how they used Unreal Engine together with Enlighten.
Unreal Engine 4 - Rivalry
Epic's Unreal Engine 4 Rivalry project shows what's now possible on mobile devices.