It is 6S. Scorpion will be changing the PCB to make it a better controller and the HV ones (12S and 15S) will be available soon as well (I'm keeping my fingers crossed for the HV ones).
Just came back from a quick run to see what was improved with the Heat Sink/Fan combo. I must admit, I've extremely impressed now. The controller performed very solid and didn't get hot at all. It was just warm and I guess the heat sink/fan made the difference. The Mega is getting a beating and it is just an awesome little motor. If Mega comes out with a sealed version of the ACn22 series, I'll be adding some to my collection.