Well, the story of Landis continues to disappoint the world and tarnish the sport. This is a tough subject that's made even less clear by really crappy reporting on the subject. I've spoken with a friend who was involved with the anti-doping regulation of cycling for years and the reality is far more disturbing--and far more grey--than is readily apparent. There are many substances that are not illegal--everything from vitamin supplements to hardcore drugs--that nearly all competitive use to improve their physical shape. While things like blood doping or HGH are clearly illegal, there are many drugs that can be (and are) taken to push the atheletes to their maximum.
The shady part here is that in many cases the tests that the regulators use do not actually look for drugs, but the effect of drugs. For instance, the test given to Floyd Landis tests a ratio of two naturally occuring substances in the human body. While normal ratios on this test are 2:1 or 4:1, Floyd was at 11:1.
What the reporting misses is that the legal limit imposed by the regulators is 10:1. What they don't talk about is that many, many cyclists are operating at very close to that limit. To make it clear, a rider that scored a 9:1 is considered 'legal', even though it may be obvious that those levels are impossible without some kind of enhancement--legal or illegal.
The issue here is that the regulators are not really testing to see if substances are used. They are merely putting an upper limit on what is acceptable. If the athelete fails the test, then there is an investigation as to why. But it's clear that the leading teams employ high-end resources to make sure that their riders are as close to the legal limit without going over. And the techniques used to do this involve both legal, illegal, and soon-to-be-illegal substances.
As a side note, there is a lot of evidence that major US cycling stars (Greg LeMond and Lance Armstrong) pushed the limits by taking performance-enhancing substances (like EPO) that were later banned. But so were the other top cyclists. Does this take away from their accomplishments? Maybe. Probably as much as it should to Floyd Landis.
The real story here should be that all professional atheletes are pushing themselves to the limit, and biological science is a major driver in this equation. Until we come to an understanding of how to deal with this issue, Landis will not be the last to have his record and image wrecked by this practice.
EVERYONE IS DOING IT. It's just a question of whether or not you get caught.