FWIW, the closed source work started at "ATI" a year or so before joining AMD, but the changes are pretty significant so it takes time to complete them and get them out the door. The open source work was definitely championed by the "AMD" folks, however.
and the community is loving you guys for that
please keep on improving the fglrx driver so that I and more folks will be able to pull out their old nvidia card and replace it with and ATI/AMD one,
at the moment it's not acceptable since it still interferes a lot with kernel internals (e.g. producing BUG messages with fully preemption, not supporting preemptive rcu [nvidia does !], hardlocking the box easily when switching through VT and X, rather unstable and slow-reacting compositing)
and don't forget: improved energy savings -> powerplay with downclocking and downvolting
from what I've read a significant difference at nvidia is that they're able to pass direct rendering through compositing (-> working fine opengl apps when the desktop is using compiz / kwin with effects)
I update those scripts very often, if i would package em i would have got maybe 1000 revisions so far, thats not needed. Also updateing the scripts only with update-scripts-kanotix.sh is much faster than doing a full dist-upgrade just to get new 3d scripts.
Well, Envy  has been available for years already for a nice click a button to install ATI or Nvidia drivers. I used to use it to update both Nvidia and ATI comps and it worked really well.
But ever since it was officially adopted, the usefulness has gone down the toilet. It used to be fully up to date, but now it takes months for new driver versions to be added.
I know Envy, my scripts have been out longer and are always uptodate. The only difference is the way how Nvidia drivers are installed, for fglrx my script also has Debian packageing, but the Nvidia installer is called directly then from that I create a dkms package just for the kernel module. Envy however creates a Nvidia debian package. I tried that approach too, but the driver packages are too different, even small changes will break it. Nice to have, but harder to adopt if something is changed.