Power MBP and connect Thunderbolt devices with only one cable I have a MacBook Pro with USB-C / Thunderbolt 3 ports. I would like to have only one cable ending on my desk to plug into the laptop. Is it possible to power the laptop through that cable and use the same cable to connect external thunderbolt periphery devices? What kind of adaptor would I need on the other end of the cable?
Yes - you can look forward to vendors shipping Thunderbolt 3 docks and have one cable going to your Mac and everything else connected to the dock:


power
ethernet
USB
video
Thunderbolt 
possibly audio in/out and firewire


I would read this review of Thunderbolt 2 docks and keep in mind that no Thunderbolt 2 dock will charge the new Thunderbolt 3 / USB C MacBook Pro.


http://thewirecutter.com/reviews/best-thunderbolt-dock/


Until the "3" version docks ship, you'll need to use "2" version cables for display/dock/whatever and a second USB-C or Thunderbolt 3 charge cable.