Also, the Nano could open opportunities for manufacturers to make very small form factor PCs that aren't even available right now, which means we can't see the true potential of having a 6-inch card by using cases like SUGO08 which are not really miniITX cases. Sure, in the past this could have been considered a small MiniITX case but the times have moved on.
vs.
It's essentially a chicken and an egg scenario - without 6-inch flagship cards, case makers won't make an even smaller miniITX case but they could if there were GPUs that could fit inside.
There is NO way to make a miniITX case this small with a GPU this powerful right now but it's possible with the Nano. Will someone make such a product for retail? Maybe but even if not this generation then in the future once HBM2 becomes mainstream. Who did it first though? AMD with the Nano. And that's why it costs $650 because it's an early adopter product that redefines what's possible in a 6-inch PCB as of right now.
If the Nano had 8-16GB of HBM2, that thing would immediately find its way in the next generation MacPro tower. I feel that HBM1 is really what held back the true potential this design to make it to the high-end but at least now AMD has full experience with HBM1 and they will be ready to go with HBM2 in desktops and laptops.
Once AMD launches Fury X2, NV may not have an answer to this card until Pascal, just like NV lost to the R9 295X2 with the Titan Z and with GTX690 vs. HD7990. The Nano is essentially just 1/2 of Fury X2 which means AMD should have no problem creating a monster single GPU Fury X2 once they bin enough Furies.