I just want to say since ive seen a lot (and i myself did the same with the reflections demo but then i deleated it) of just rendering out (or capturing it “live”) the demo fly throughs that i will assume come with the Elemental video as im sure there will be a ton of those shown on youtube. but create your own scene. The Mantinee tools are not very complicated to use once you figure out. if your not good with animation its not very hard to do camera fly throughs and i would think the sceney in Elemental would be perfect to try that out.
So i would suggest for people who get the assets once they come out (hopefully this month as they said with 4.1) while it may be tempted to just render a video or capture the demo “live” and upload it to youtube. itd be more cool and make you feel creative to do some of your own for example for the reflections room demo there was a premade fly through but i took a few minutes (it didnt take that long) to create my own
It would make you feel more creative and also a great way to impress your friends. Honestly ive found the engine has encouraged me to do more creative videos ive even figured out how to import some charecters and animatoins from DAZ 3d not perfect (hair and eye issues) but at least something to play around with 
I just post this because ive seen a lot of such renders of the default scenes from the room and relfections demo and for people searching for unreal engine 4 videos online its better to have more unique videos even if its just a diffrent fly through :-).