If blizzard are going to nerf knife juggler, then ideally what I would hope for is that they keep the mana cost to 2, keep its 3/2 body, but make the ability activate after you PLAY a minion instead of after you summon a minion so it only activates if you summon a minion card from your hand. The ability is only broken when used with cards that summon multiple minions on the battlefield at once.
But to be honest I do not even know what cards are going to be nerfed, all I hear is speculation. But what I find unfortunate is that people want cards to be nerfed but they will complain if the card gets absolutely destroyed. When blizzard nerf cards, they tend to nuke them out of existence which is why I am not looking forward to the nerfs because some well known classic cards may end up being rendered completely unusable.