We're finally starting to get single gpu's with the grunt to make mgpu the fossil it deserves to be. A pair of 480's would provide a crappy experience overall when compared to that from a single 1080, An experience I'd happily pay the extra 200 quid to avoid, The 480 is a different class of card to a 1080 & 1070, It'll sell well at it's price point which is what it needs to do, Taking into account how bad supports been lately no-one should be considering a multi card set up with GP 104 chips available now & Vega on the Horizon.
yes, i do agree mgpu past experience is bad, but you saw the video, koduri's argument is sound, shrinking nodes is not a given anymore, complexity of 10-7nm could be too hard to do, the price could get out of hand, there is so much ppl can afford to pay.
mgpu scaling is a very logical solution, cost is a major incentive from vendors to parteners to users, and could be the only way to go in few years.