"The title itself may disinterest you. But believe me it is not.
In words of Fedora:
"Currently, most graphics modes are initialized during the X
server startup. Kernel Modesetting moves this process from the X
server's DDX drivers to the kernel, and it enables several new
Improved Graphical Boot
Faster fast user switching
Seamless X server switching
Graphical panic messages
"So basically fast user switching will be faster and smoother,
making Fedora more pleasant for non-technical and casual users.
Memory management will be better over all."