At the moment, priests do have revitalize to heal themselves, even if they go all damage.
This may be a good ability in future, when more damage is dished out, so that each class has their own way to make it easier on the healer while they're doing what they're supposed to do. At the moment, however, I still have content that uses the current ksill sets. In addition, whether it'll be an ability, a set bonus or a charm, it'll need careful balancing because the priest class can already recover health very easily.