The article is pretty light on details. What's revolutionary about 8 GPUs in a PC on a shelf?
I'm not sure what the revolution is. Unlike open-source software, open-source HW design doesn't actually give you something that works. The truth is that Nvidia solutions partners like Exxact will deliver a 4 GPU box for ~$9K.
This is an aside, but I've noticed a lot of the best Ars Technica content is coming out of their UK arm lately.