I think only real problem with Shard of Sacrifice is when it comes to Arena Deck design. If I must always desing my decks against SoSa - I have to make some kind of stall deck. And how many us like always play against well designed stall decks? I mean low damage, high heal/hp deck, so player with SoSa don't benefit what you have in field. Basicly you need only one Morning Glory to beat up SoSa -deck when all other cards in deck are just for maximize health over long game. Playing succesfully against good stall, you need good staying power, you don't want deck out, you don't want too much damage. Eternity is must, healing is must, purify is good one.. BUT if my stall deck include Deathstalker, Unstoppable and Quintessence. All other cards just for keep my deck alive. It's gonna be very long annoying game, even if you have remotely good deck against that. You have 6x purify ?, but can you heal enough?
My current arena deck is anti-SoSa deck - so there is only 3 (x2) creatures: Ulitharid, Purple Nymph and Death Nymph. Damage output is very low, even with Morning Glory. If all goes well you see only quinted creatures. With Wings spam (x10 in deck = 50 turns) and miracle + divinity shard spam deck is pretty solid. Still I beat it with my speedbow about 5 times.
SoSa is most stupid card at the moment, kinda anti-intellectual brainfart. Can't see how this card can bring something interesting to this otherwise good game.