I can sum this up now because it has been talked about already in forum posts already, and much information has come to light.
Commenting on this realism degree we see from UE4, and as it relates to it being a part of iClone in the near future:
1) iClone realtime is based off of Nvidia VXGI, whereas Unreal uses its own Global Illumination system.
Thus iClone cannot match certain effects and lighting features UE4 can achieve. VXGI will be the bottleneck, not iClone's intended innovation.
2) the digital figures in the Unreal video are not the CC3 or Daz based model set. They are separate creations with much higher resolution as far as polygon count and texture mapping size.
If you import in your CC3 characters to UE4, you will not see the same LOD that these figures have. And even if you could reverse import in these figures in iClone, you would not have them walking around in a scene, or compatible with the animation features.
It will not be iClone that innovates this movement forward, it will be a larger industry hardware and OS move that allows for this.
Do I want this in iClone ? YES YES YES YES YES!
But I think it is not accurate to imagine this is going to just appear by sheer artistic desire on our part. We could be surprised, but there are specific and real structural barriers presently.
Just my $1.02 cents.