I noticed that players use this card mainly for it's batttlecry not the minion, which is the case for me as well. It is frustrating in the sense that without the coin you have to wait till turn 4 to be able to play it, that and the fact that you can't play other cards that don't cost 0.
Now 4 mana for a 4/4 with battlecry seems a fair price, but if you only care about the battlecry 4 mana is pricey when in the back of your mind you never cared about the extra 4/4 minion that comes along with it. I wouldn't mind if they changed it to be 1 mana for 1/1 minion instead. Heck, I I wouldn't mind either if they changed it into a spell that costs 1 mana and makes 1 of your minions permanently stealthed (or until he attacks) whereas Conceal put all your minions in stealth but only for 1 turn.
This way we can pay the card for what we actually wanted it to do while not minding the loss of the 4/4 minion.
What are your thoughts guys?