Years back it seemed very likely that the shuttle run would be something that would soon become part of regular open testing. I really liked the idea of it because I think if you are testing general fitness of athletes like CrossFit does running is a crucial component that is overlooked in the open. Not that shuttle runs would be the perfect way to test it because it would be more about the athletes ability to change direction efficiently than it would be about actually running.
I think running is more of a true test of aerobic capacity then the other monostructural machines used in CrossFit because it does not pay to bigger or more powerful, it evens the playing field for all athletes. Also it is a much better way to look at athletes general athleticism