PEDs are more about being able to train harder, than improving performance with the same amount of training.
If Lance ever does fall, all the American money will disappear from the sport, I reckon Europe would keep going though, since it's used to the whole drug scandal thing.
Valverde was banned on the basis of evidence gathered four years ago, a lot has changed in the time since then with regards to things like the biological passport and new tests for CERA. Of course, the dopers will have moved onto something else.
The thing that bothers me most, is all the recent talk about motorised doping.