Resolution and polygons aren't the only things behind increasingly lifelike 3D worlds. Lighting plays a huge part as well.
French artist koola has shared some truly extraordinary images and footage of his work in Unreal Engine 4, with particular emphasis on the work he's done with things like lamps and sunlight.
If you need some reference to dream for once devs can stop tailoring games for the 360/PS3 and can really kick the tyres of new hardware (not to mention the PC), then these should do the job nicely.
If you want to see some static images to go with the video work, you can see more of his stuff here.