Note to myself:

When the laptop isnt used for some minutes and the power saving function tries to turn off the screen, it is nicely blended. It looks like what we all want for the brightness keys. This also works independent of the nvclock and smartdimmer applications. Thus the kernel gives an access to the screen somewhere and one application is using it

My packages do not handle brightness and brightness keys, since they are supposed to work out-of-the-box. So, I think you can safely bind the smartdimmer's commands to keys by using the utility 'compizconfig-settings-manager'.
No. Users have reported it to work on intel video cards and some ATI cards only.
Anyway, I suggest you to give a try to the 'nvidia-bl-dkms' kernel module found on this repository.