Description of problem: powertop notices the syndaemon 20ms polling loop which prevents the system from entering lower CPU power states. http://www.bughost.org/pipermail/power/2008-January/001234.html includes a patch.
After ack from jeremy, I applied the patch from the above mail message, and changed the default poll to 200ms. This is built in synaptics-0.14.6-5.fc9.