The Pope has spoken but not issued an encyclical. The fact is that Catholic hospitals across the fruited plain (and around the world) have followed the procedure that is being done with Terri Schiavo and they are evaluating procedure in light of the Pope's recent comments but his words have not become the "formal position" of the Catholic Church.
I just read the official Church's opinion on this matter. It is lengthy and has so many reasons why people may do what is being done to Terri that they may as well have not issued an edict at all. One of the reasons is even for money...if the procedures become burdensome or expensive, etc.
i suppose that is how Catholics not in keeping with the catechism justify their actions to themselves in this situation. our priest gave a clear and concise sermon based on canon law and natural law. in spiritual matters, i defer to the Pope.