what is this...NEW Assist & Slip Clutch Pack provides a slip feature on downshifts to reduce loading of the driveline; 
It's only NEW to the Harley Big Twin models, otherwise it's fairly old news to the Japanese and Italians and even the V-Rod.
The clutch is designed with built in ramps that increase clamping force when the clutch is being driven by the engine torque, but reduces clamping loads and allows some slippage when the clutch is being driven by the rear wheel and trans. This has many benefits. One is that it helps reduce shock loading on the drivetrain under heavy decel and when banging downshifts without matching rpm. Another is that when you bang one of those downshifts and the tire tries to lock up momentarily, the clutch slip can reduce any rear tire traction loss. Another is that the clutch springs and the lever pull can be lighter because the ramps increase clamping loads on the clutch plates only when needed.
As far as I know this is only being used on the CVO models for 2013. I would assume it will eventually be made standard on all Big Twins after the 2013 CVO owners perform the beta testing.
Jerry