I think this kind of cards is very hard to balance. Now they suck, because it's pretty hard to make them stay on board long enough, to utilize them at least once. Though it's not too difficult to imagine what would have happened if they were more sticky (at least some of them). I believe that making them battlecry and 1 mana (Shaman and Prieest) or 2 mana (Warlock, Paladin, Hunter) would be the best solution.
I think this kind of cards is very hard to balance. Now they suck, because it's pretty hard to make them stay on board long enough, to utilize them at least once. Though it's not too difficult to imagine what would have happened if they were more sticky (at least some of them). I believe that making them battlecry and 1 mana (Shaman and Prieest) or 2 mana (Warlock, Paladin, Hunter) would be the best solution.