This is obviously the only choice for a comparison now, as Apple has not released the desktop version of their processors. But, even this comparison is embarrassing for Intel...their top of the line processor is only 1.5 times faster than Apple's first mobile processor, and the power difference between the two is massive, almost three times as much. Apple really has built an impressive architecture with the M processors, it's going to be very interesting when they release their desktop processor that can take advantage of more power, space, and cooling capacity allowed in a desktop case.
Honestly, I can't wait to see what a truly unleashed M processor can do, and what Apple plans to do for the second generation of the processors they are building, which are the most efficient out there, and have a shot at being the fastest overall.