Hm. I enabled it in latest preview build, setup sample scene, and I can’t see it working. I mean, the scene is flat as usual. For testing I just enabled Skylight, and disabled directional light.
For reference, I had setup scene similar to the one on screenshot. Just composed from default meshes in architecture folder.
Screenshot:
https://dl.dropboxusercontent.com/u/70400220/Unreal/Skylight-noao.png
Edit:
Here the same scene with Skylight + DirectionalLight
https://dl.dropboxusercontent.com/u/70400220/Unreal/skyligth-directional-noao.png