IEEE Spectrum reports Intel Talks Thunderbolt 3: One cable to rule them all, and it’ll be optical in 2016. A few excerpts:
... the vision behind Thunderbolt 3 was to create one cable that allows users to connect every type of peripheral to their computers, and to do so with as much bandwidth but as little cabling as possible. More specifically, what the company was trying to do with Thunderbolt 3 was to develop a high speed I/O over a single wire for users who create 4K video content, make it as power efficient as a USB, and keep product cost low enough for use with a client platform such as a laptop (as opposed to a server).
... Thunderbolt 3 has a 40-gigabit-per-second bus that’s four times as fast as the new USB 3.1 and twice as fast as the previous generation of Thunderbolt. What can you do with so much bandwidth? Well, for starters, you can run two 4K 60-hertz monitors at the same time using Thunderbolt’s built-in support for the DisplayPort 1.2 protocol.
... Having fast external PCI Express support allows another interesting feature that Intel demonstrated: ultrafast external storage. By using NVM Express—a specification for attaching solid-state drives to PCI Express—users will be able to connect these new drives to any device (including future Thunderbolt 3–supported laptops) with up to four times the transfer speed of the fastest SATA drives around