I'm always reminded of the complexity of running Linux when I reboot after a kernel upgrade because it kills my Nvidia driver and I need to reinstall. This can be painful unless some extra repos are enabled. In my case I use atrpms and simply run a 'yum search nvidia|grep x86_64|more' to pull a list of available drivers, from a run level 3 (command line) boot, and reinstall the latest Nvidia driver. It's not the hardest challenge in the world but it is another reason most people can't use Linux (at least not with the best available drivers).