Somehow you have the development repos set to active (could become a major issue). Please post the results of:
Any time you tell yum to get an unspecified version of a package it will get the most current package. So when you asked for kernel-devel it got just what you asked for. You can either update your kernel to the current one or ask for the specific kernel you want.
(above) will tell you what is available in the repo (normally only the last two kernels).
You may just be better off adding the Livna repo (fedora approved) and installing the nvidia drivers via there kmods.
Installing the nvidia drivers from their(nvidia's) website has (at least in the past) been known to replace certain OS components with versions that are not compatible with other things (this is getting better).