Well I use the stock mach_kernel which is patched by Clover (rev2435 provided by amokk) when I boot, with the MacBook Air 6,2 SMBios. Power Management is handled by the kernel (XCPM) and I have this P-States : 8,24,25,26,27,28,29,30,31,32.
There is a big hole between 8 and 24. Is someone success to have more P-States ?
EDIT : RehabMan seems to have best result with MacBookPro 8,3 if someone have tried tell me