I'm sure has been already discuted here but:
In EP 3 revisited, maybe Adywan could cut any Vader name references and cut the Anakin story when Palpy find him on Mustafar (cut the "he's alive, bring the medical shuttle" lines). No Vader under the mask in EP 3 at all. That way the Vader/Father thing could still work in Empire.
I personaly think keeping the father surprise for Ep 5 is a must have.