Fast charging electric vehicles is widely understood to encourage electric vehicle adoption. In Japan, when the CHADEMO network was installed (in 2008) research has shown that event increased electric vehicle utilization (see http://greentransportation.info/why-is-fast-charging-required-for-widespread-electric-vehicl). It's thought that simply the presence of the fast charger network let people get past the range anxiety issue.
The controversy is that the SAE is not simply adopting the CHADEMO standard. Instead they went through a standards process of selecting the best technology and have developed a new charging connector that's based on the J1772 connector we're familiar with, but that adds a pair of DC pins.
As the picture says, this connector supports: single phase AC, three phase AC, "Home DC" and "public DC" (which sounds like two levels of DC charging.
The DC portion is the two big pins on the bottom. To send control signals between car and charging station for controlling the DC charge rate, it uses HomePlug Phy which is a smart grid standard for sending data communications over a power line. It's related to Power Line Ethernet.