iOS could do with a new look, but I would far from call it an urgent requirement. OS X? Nope, it works as it is was intended to - why does it need a new look (again)? Do you spend your days staring at the OS elements, or actually using them? I understand it needs to be pleasing to the eye, but Mountain Lion is as far from boring or stale as I can possibly imagine.
If your eyes need stimulation that much, go out for a walk and look at the sky, the plants and the rivers.