So long-term I think this is actually great news, as it isn't quite the GPU killer everyone had feared. It beats out GPU rigs on price alone, but as I stated only because GPU prices are so over inflated right now. Once the E3 hits the market GPU prices will come back down to normal and probably become bargains. At that point I expect you can put together a 6x RX580 rig for closer to $1,100 by then, so it will be a even match considering the GPU rig will have other uses and resale value so worth the extra $300.
With shipping and psu it's closer to $1100 anyway. And to put together a 6x580 gpu rig for $1100 would require the gpus to cost around $150 each unless you already have all the other parts (which should still be factored into overall cost, really, but comparatively makes a little more sense). I don't think I've seen 580s drop that low in...well, memory, really, but it could happen, especially if ASICs drop demand significantly. But there are already next gen gpus available, and as AMD and Nvidia keep producing new generations, they'll make the ASICs obsolete. I don't think gpu mining is dead, but I do think it's going to become a game of upgrading your gpus a lot more often...