This is exactly the kind of game-changer I've been hanging out for.
While system RAM has been charging ahead to a point where you can easily and affordably get your hands on 128GB of RAM in a typical workstation, GPU's have been lagging behind with paltry increases of a few gig here and there, making full-time GPU rendering a tough ask for artists, despite the speed benefits it may offer. We're now seeing cards around 24-32 GB (with pretty serious price premiums), which inevitably will come down with time, however this is the first genuine 'disruption' in GPU memory progression we've seen for years.
I'm looking forward to this technology rippling down once it's in formal production, and not just part of a developers kit.
http://www.anandtech.com/show/10518/amd-announces-radeon-pro-ssg-fiji-with-m2-ssds-onboard