I am completing a Master's of Science in Biology (mostly molecular biology), have two undergraduate degrees (one in chemistry and one in biomedical biology), have taught human anatomy and physiology at a university level and am beginning medical school next year.
I am not an authority on this subject, however, I am willing to bet I know enough to make the educated statement that too much of any "drug" is often toxic in one form or another. To assume any of these guys is healthy is like burying your head in the sand and pretending a problem doesn't exist. I agree that the diuretics have been the cause of many a competitor's problems, however, to assume that habitual, exogenous steroid use (at their level especially) is safe just because you don't see any effects is really not a good idea.
Before many of the obvious physiological problems make themselves visible to the naked eye, many diseases progress throughout the body and only in later stages does it become obvious that there is a problem. In other cases however, it can be the opposite.
Therefore, to defend the abuse of steroids that is being seen in this sport and demanding "proof" is like winning an argument by taking your toys inside. There will NOT be any published studies regarding this because the studies would be illegal and expensive. There is probably data out there, but we will never see it.
Anyways, just my two cents, however, I would tend to side with those that are coming to the conclusion that just because these men look healthy on the outside, they are likely not 100% inside. However, I do hope I am incorrect as it would be great if they were all completely healthy.