The particular feature request is usable and works, i tested it here and if you don't give a damn about acpi-cpufreq(which is not autoloaded at all) you are not affected at all. If this patch existed 1.5 years ago i wouldn't have needed to change the dip switches of my mainboard to undervolt.
I use acpi-cpufreq. And I have a very strong opinion about it, as I don't want it to be broken in _any_ way (I depend on it very much). then you are the perfect person to report issues if there will be any (which i hardly doubt). You didn't even tell us if the -7 kernel works on your system. It adds sysfs functionalty if you don't change something on it nothing happens.
-- Tobias Powalowski Archlinux Developer & Package Maintainer (tpowa) http://www.archlinux.org tpowa@archlinux.org