I have ATI Radeon HD 4570 graphics card. Ever since I started using Fedora, I couldn't properly install drivers for my graphics card. It's hell lot of difficult to get ATI drivers working on Fedora. Last week, when I installed proprietary ATI drivers on F16, the OS just stopped working. It would stop loading just before the login-prompt. This time I decided not to pursue the problem & did a rollback.
Somewhere on the internet I found this:
echo low > /sys/class/drm/card0/device/power_profile
It sets the graphic card to low power consumption mode. Upon using my laptop in this mode for a few days I noticed that this has solved the overheating problem to some extent. So I would definitely recommend it over installing crappy ATI drivers. Still its far from what I get on Windows Vista so I am considering switching to Ubuntu when its next LTS version is released.