Reviewers: make sure to test mining performance of these cards. Not that we care about that, but to give us an idea of whether it'll be possible to actually buy these things.
The Vega frontier board is clocked faster than the Vega 64s and has twice as much RAM, and RAM bandwidth.
I'm going to take a guess that these are going to be slightly less attractive to miners than the Nvidia 1070. Wouldn't like to put money on it though.
--edit-- Power consumption on these will be the deciding factor, possibly. Nvidia seem to have a far better handle on that lately.