Min, it varies from state to state. Some states require reporting of all cases - even suspected cases. Others give clergy full immunity from the requirement. Still others have found a middle ground for the time being. The basic issue is the balance between religious freedom and protecting children - both critical underpinnings of our society.
I think we can expect the states to continue to enact more mandatory reporting laws. But those won't apply to past problems. For the short term, the crucible will be the civil courts. As Lady Lee points out, there are plenty of holes in the "we don't have to report" defense. But unlike the Catholics, the difficulty will be in getting the R&F dubbies to rise up and make it clear that they won't tolerate it anymore. ( I'm a bit sceptical on that one though)