A lot of new systems are going to be coming out with USB-C / Thunderbolt which allows you to use pci-e bus over it. Specifically using an external GPU over USB-C, for example the Razer Blade Stealth / Razer Core.
Since this is a new feature I am assuming we won't have support right away. Does anyone know if this is supported and if it is what is the performance like?
Well since it has been awhile I figured I would post the results that have been coming out on this.
So far some one running Arch on an XPS 13 and using the Razer Core has gotten an Nvidia 970 to run.
You can read more here for anyone who is interested.
https://www.reddit.com/r/razer/comments/4xwlt6/razer_core_gtx_970_on_xps_13_9350_arch_linux/