This brings a good question - is testing working? I heard in the talk show that lots of baseball players are still using it and they are confident they will never be caught. As soon as they find a test for HGH - may be the players will move on to something else that is undetectable. So - the labs/black marketters and players will always be a step ahead of MLB.
I think the testing has somewhat changed the culture. Previously - almost everyone was cheating and it was part of MLB culture. It used to be like a road where there are no cops - so you can speed to stay ahead and you probably will as everyone else is speeding. I think right now the players know exactly where the cops are in that road - so they can slow down when they need to but still can speed if needed and will not get caught unless they are stupid like Manny.