According to rumors, the touchpad of the DualShock 4 can be mapped just as the touchpad on your standard laptop. The DualShock 4 takes advantages of the built-in USB HID drivers and needs no additional driver support in Windows beyond what is already support in the OS natively.
Of course Sony could change the identifier on the USB controller prior to launch to make it incompatible without some sort of driver support, but that does seem to be unlikely at this point according to sources.
Read more about it here.