See the feature highlights for the Unreal Engine 3 from GDC 2012.
Unreal Engine 4 - Rivalry
Epic's Unreal Engine 4 Rivalry project shows what's now possible on mobile devices.
Allegorithmicís Substance Engine for Unreal Engine 4
Allegorithmic's Substance Engine is now available for all Unreal Engine 4 developers.
Unreal Engine 2014 Gameplay Reel
See the highlights of some of the games built with Unreal Engine technology in this gameplay reel.