Will 'PowerNow' Cause Trouble in Linux?

Vandermar asks: "AMD's 'PowerNow' promises to vary clock speed in 50mhz increments on the fly similar to Crusoe. If I remember correctly, Linus had to make changes to the Linux kernel to keep it from freaking out when the clock speed changed. Will the variable clock speed of AMD's new mobile chips require changes to the kernel (or will PowerNow need to be disabled)? How was the kernel modified to allow it to run on Transmeta chips?"