Skipinnz: You are absolutely right about the fact that one should never prune hydrangea until their blooms have died. I prefer to wait until the following fall. The flowers buds are only produced on last years growth. To cut any hydrangea back limits it's potential, especially if they are newly planted.
Therefore Rose:P Be patient. I have seen some Easter Lilies and Mother's Day Hydrangeas turn into beautiful monstrous shrubs any gardener would be proud to own.