With the level of doping it takes to win an Olympic medal in women's distance running, I don't predict anything. The level of natural talent with KT is remarkable though. Lets just say if she did what the top international female distance runners are doing, the results could be really nuts. But she is too well-adjusted to try it.
US sprinting is much more experienced at playing the game. Major doping busts in the sport are relatively frequent, and I doubt a single Olympic gold medalist in the major sprint events has been clean in 60 years.
The thread is silly, however. Different sports with different rates of development.