See #200 for some answers. Some also say his new honey wants a Catholic wedding and they can't have one unless Terri dies. BTW, Michael said on Larry King that he had both his parents "allowed to die" in this same way he wants for Terri, because their lives weren't worth living! And he is a nurse.
This is not a reason to kill Terri. Michael and Jodi can have the Catholic church wedding they desire, but they must obtain it in steps. First, Michael must divorce Terri, and give guardianship to her family. Her family can seek an annulment on her behalf, and would likely get it. Michael could marry Jodi in a civil ceremony until the processing is completed. Then they can have their ceremony in the Catholic church. The kids get a legal father, Jodi gets her wedding, Terri gets to live. Win/win, right?