Jeff,
You are partially correct. There were 2 cases reported and then a 3rd. However, the 3rd case was originally diagnosed as death due brain cancer and only considerably later changed to PML. Due to the serious immune-suppression in patient #3, it is no longer considered a Tysabri related death.
Patient #2 is indeed alive and undergoing treatment. PML is not 100% fatal if diagnosed correctly. More like 50%. Note that patients have been dying of PML since long before Tysabri or Avonex were even developed. There are always going to be more PML cases in severely immune-suppressed patients unless better drugs are developed that can quickly cure it.
Back in ancient days, the Druids thought black cats were human beings.