As you know, ELRepo provides the Nvidia driver for EL kernels but not for kernel-ml or kernel-lt. People running kernel-ml/lt can install the driver by downloading it directly from the Nvidia site. However, kernel version 3.13, as currently offered by kernel-ml, is known to have a problem with the latest Nvidia drivers. Fortunately, there is a fix for this issue. The detailed instructions are posted by CentOS developer Johnny Hughes on his blog.
Thanks, Johnny!