For the longest time I have wanted Priest to get a scry effect. Look at your top card and choose whether to out it on the bottom of your deck or keep it there.
In average Renolock decks, there are at least 9 essential cards in the control matchup:
Jaraxxus
Leeroy
Manipulator
PO
Reno
N'Zoth
Twisting Nether
Brann
Kazakus
So you have a good chance of forcing a Renolock to discard a VERY high profile card. I will run this in my Renolock deck for a while and see how often it gives me the win.
The top aggro decks in Wild also have key cards that let them function. Murloc Warleader, Arcanite Reaper, Leeroy, and Living Mana come to mind. If I made my opponent discard any of these I would be overjoyed. Not to mention things like Tirion. Imagine if your Control Paladin lost Tirion - poof, gone! That might only happen one out of 10 games, but that doesn't sound too bad to me.
The word "interactive" in Hearthstone means that there are things I can do to reduce the potential effect an opponent of mine might inflict upon me. A silence isn't non-interactive, because I can choose what I play for them to silence. Wild Control Shaman has multiple cards in its deck just for baiting out hard removal so that their big stuff can survive. That is interaction.