The 4k Doom results were nothing special, Googling the newer Doom Vulcan reviews show that a stock clock 1080 hits an average of 61 & minimum of 56 at Ultra 4k and a Fury X hits 55 & 46 respectively.
Taking that into consideration makes the result on Vega not look that good, The problems all the hype where people are acting like the drivers used were totally out of whack for Vega as if there will be a massive increase once they're fine tuned, The thing is I do not think they would have shown it if the drivers were that bad, They may get a bit of an improvement but I doubt it'll be massive like some are hoping for.
If they can give us a 1080 beater that wins in DX11 titles as well as DX12 & Vulcan I'll be happy and I imagine they will too.
Think Vega is going to end up somewhere between the GTX 1080 and GTX 1080 Ti (closer to the gtx 1080), which would make it just slightly slower than two RX 480s in CF. If priced competitively it should sell well.