With Alex's brand new patch, hwmon drivers can now be loaded for the I2C thermal chips found on many ATI graphics cards. In other words, we finally have thermal monitoring and fan speed support for the open-source ATI stack! Though it's not finished yet as the hwmon readings aren't exposed to the Radeon DRM yet so it isn't yet able to leverage this data internally. This though will come. Additionally, Alex is still battling support for voltage adjustments when switching power states, fine tuning the re-clocking algorithm, and letting the Radeon DRM read the AC/battery power state.
This newest power management code can be found in the drm-radeon-testing branch and will hopefully be ready to go in the mainline kernel by the Linux 2.6.35 kernel this summer. Details on the newest ATI power management work can be found in Alex's blog post.