See the Unreal 4 engine in action in this trailer for Primal Carnage Genesis.
Unreal Engine - Open World Demo Collection - Free
Epic Games are giving away assets from their Open World demo, to be used within Unreal Engine 4 based products.
Space Hulk Deathwing - Trailer
The Unreal 4 engine shines in this action-packed trailer for Space Hulk Deathwing.
Dynamic Lighting Gameplay with UE4 and Enlighten using Blueprints
Geomerics have posted a detailed article on how they used Unreal Engine together with Enlighten.