Group Policy Preferences

I've been trying to work out how to control the power settings on the computers centrally.

After some research it seems that Microsoft have enabled these features in Group Policy Preferences. Now whilst being inherent in server 2008 it does seem to be that you can get them in a Server 2003/XP environment by downloading the Client Side Extensions, XML Lite and having a Vista machine running the server 2008 RSAT. So...

Has anyone managed to impliment group policy preferences in a 2003/XP environment? Was it successfull? Are there any problems I should be aware of?

Failed completely, that was over 2 yrs go tho. Windows 2008\Vista should be able to do it out-of-box.

The 'old' 2k3 way to do it was with EZ GPO.

EZ GPO : ENERGY STAR