3 out of 180 isn't bad, not good, but not as bad as in previous years.
Astana and Cofidis being booted out will hit the cycling community hard. The teams do not want this, and it should affect their eligibility to compete in the coming races.
Astana being banned from competing in The Vuelta would really show the cheats that they are not going to be allowed to continue cheating. But they will be allowed to compete, as will Cofidis and teams will continue to take the risks.
Banning Cofidis from next years TDF would really have an affect, and is possibly the most severe punishment.
If the regulatory bodies punish the teams, the teams will start to make sure their riders are clean as they are the ones that will suffer