Power MBP and connect Thunderbolt devices with only one 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.