I should add that making nvidia-driver conflict with later kernel versions for which it has not been tested is only an *example* solution,but clearly not the only way to keep apt-get upgrade working properly with nvidia-driver. A more flexible solution would be to create an optional dummy package, nvidia-dkms-compat, with the same version as nvidia-kernel-dkmsbut which conflicts with later kernel versions than the ones where nvidia-kernel-dkms was tested. Users that want to keep the current informal status can avoid installing nvidia-dkms-compat and rely on the description of nvidia-driver to choose newer kernel versions.
Users that do install nvidia-dkms-compat will be alerted through the usual apt methods that there is an incompatibility with a newer kernel. Regardless of how this is solved, I think an important goal is that apt-get upgrade should work properly when nvidia-kernel-dkms is installed;this means that a newer kernel on which nvidia does not build will not be installed by default, not appear as a candidate upgrade version. thanks,--jack