Those scripts just disable or enable the files that fglrx replaced with the standard installer. I am not sure if that's something i have to like or not, for a distro like U >= 10.04 it is useless as
Code:
update-alternatives --config gl_conf
update-initramfs -utk all
ldconfig
and changeing/removeing the xorg.conf would even allow to switch to nvidia driver. Basically those things should be done with update-alternatives on a debian/ubuntu system, it is just a hack that you don't need to remove the complete driver in order to use the onboard chip.