The USB cable for the Commander Core XT has a split off of it with another USB 2.0 connector.
While all 9 pins are there, only 4 of them are actually connected. This is pretty cool - it lets you line up a normal USB 2.0 cable with the polarity key in the right place so you can put any USB 2.0 device on here.
What's going on here? Well - USB 2.0 headers have 2 USB ports on them. Each port uses 4 pins with the 9th pin being a ground for the housing. Most of the Corsair controllers - including the Commander Core XT - only need 1 of the USB ports but take up the entire header. This leaves open USB ports unusable and with the scarcity of USB headers on motherboards these days, having every USB port available is nice.
This will work, as-is, with the Ligthing Node Pro, Commander Core (Capellix Edition), and Lighting Node Core. Just plug the cable in and off you go. With the Commander Pro, you have to have it offset - the 4 pin row on the Commander Pro's connector needs to connect to the 5-pin row on the cable. So it can be done if you are careful.
Personally, I think this is pretty frakking awesome and long overdue.