This card is one of many reasons I played Hearthstone than other card games, the cards are enriched with WoW stories (mind if i roll NEED?) and this card is simply match in both its art (Dalaran Library means one of the biggest source of Magic knowledge in Azeroth, study HARD Violet students!) and its effect (Ssh! Silence!)
Whether or not it takes off is one thing, but being able to silence two minions on one card for 2 mana is a big deal. As such, I could see the "can't attack" package - Ancient Watcher, that new 3 mana 5/6 "can't attack without spell damage", and perhaps one or two cards I'm forgetting are still in standard - they have potential with this.
Hell, turn 2 Ancient Watcher into turn 3 5/6 into turn 4 silence + something else (maybe 2 mana removal) is pretty decent, attack with a 4/5 and 5/6. Of course, the problem with it all is consistency, but when it does happen it's fairly high tempo, so hopefully it's in a deck that can make up for that inconsistency by either including more silence tools (ie. priest), or having a solid shell around those shenanigans (potentially something like old school style handlock).