Looking at the video it seems very unlikely it's UE4. From the movement alone it's either the same engine as New Vegas or Skyrim used, possibly updated.
I don't think it's gamebro unless there have been some significant improvements.
-Able to see though windows
-World seems much more detailed and colours more vibrant
-The reddit leak suggested a new engine (If you believe the leak was true)
It looks much more like rage did, so I think it's built on ID tech.
To be fair though, animations/movement aren't indicative of what game engine is being used
I reckon it's not Gamebryo too, if so I'm wondering what the implications to modding are going to be?
It looks much more like rage did, so I think it's built on ID tech.
You sure?
FPS games on cryengine for example all have really similar movement.
I'm not an expert in this at all but from a quick look around movement/animation seems to be a part of the engine.
Not being gamebryo doesn't mean it won't be modable, it just means that suitable tools for the engine will need to be released.
I think the likelihood of mods being available is very high. I expect FO4 mods will all be via steam workshop and will be paid for only. (Given that Skyrim was the initial premium mod test vehicle.)
I've pre-ordered from G2Play for £22.
I've bought plenty of games from G2Play over the years without any problems.