Suse 9.3 does Centrino straight out of the box.
Including true throttling of the processor. Throttling even takes place when the laptop is on AC power, which allows it to run cooler. My Thinkpad runs at 600Mhz when the processor is at low loads or idle. and when the demand increases it adjust the speed between/up to 1.5Ghz. I've yet to find another Distro that does this properly.