The correct nerf

Blizzard has announced that they are going to be making some adjustments to core cards in Hearthstone, probably coming both from basic cards that everyone has and the Classic set that is going to stay in their new Standard format forever.  There are a few things people are suggesting that they deal with but the really standout issue that Blizzard has to resolve is druid combo, which is based on these two cards:

Force of Nature / Savage Roar can smack your opponent for 14 in the face from an empty board.  (Roar makes each tree do 4, and then you personally do 2.)  People absolutely hate that when playing against a druid you cannot let yourself go below 15 health or you just die next turn.  It gets even worse when you let the druid have even a single extra minion in play, because then you might not be able to safely be below 20 health.

The combo is incredibly effective, so much so that nearly every druid deck runs it.  It is so prevalent that the designers rightly see it as a huge design constraint - how do you make other cards good enough that people won't want to run the combo?  As such, there is definitely real consideration that the combo should be nerfed.  But how should they go about doing this?

Consider Fireball.  It costs 4 and does 6 damage.  Force of Nature on its own costs 6 and does 6 damage.  It is basically a giant pile of junk, and would never see play again if Savage Roar was gone.  Savage Roar on the other hand is a solid card and appears in lots of decks with or without Force of Nature.  So clearly nerfing Force of Nature is just going to relegate the card to the dustbin, while nerfing Savage Roar might leave it still useful.  There is a third option though, which is to buff Force of Nature while nerfing its interaction with Savage Roar specifically.

A simple option is to raise the cost of Savage Roar to 4.  That pushes the combo back to turn 10 instead of turn 9, and generally weakens the combo deck by destroying the possibility of comboing with 2 Roars at once.  The trouble with this nerf is that it probably leaves these two cards as only useful when comboed together and otherwise as bad options.  I don't much like the idea of designing cards so that the only way they can be used is in degenerate combos that blow people up from hand without any lead up or counter.  You could still see Roar used in druid decks that flood the board, but this nerf would indirectly punish them a lot because they already have a ton of 4 cost cards that benefit from a big board.  (Cult Master, Soul of the Forest)

If instead you focus on nerfing the interaction between the cards you could make Force of Nature a single 8/8 with Charge that died at the end of the turn and this would make things a lot less ridiculous.  It would be more effective on its own without Roar and would likely see some play as a powerful finisher.  However, the combo would only generate 12 damage instead of 14, and if you did manage to cast a second Savage Roar you would only up the damage to 16 instead of pushing it to 22.  A 12 mana combo that does 16 damage is still a threat, but it feels a lot more appropriate in terms of resources to reward ratio.  The trouble with this change is that it does alter the flavour of Force of Nature in that it summons a single tree instead of a horde of them.

Fundamentally I think you have to approach this from the perspective of trying to keep the cards viable individually.  They are so powerful together that if you nerf them randomly until the combo is bad, then the individual cards are almost certainly garbage.  That seems like a waste and certainly would be sad for the druid class in general.  However, from the way that Blizzard has nerfed things in the past I would not be surprised if Savage Roar suffered some absolutely brutal nerf like reducing its effect to +1 instead of +2 or raising its cost to 5.  Either of those would completely destroy the card's viability and render both combo pieces worthless junk.  This has been the fate of virtually every card Blizzard nerfed in the past, and while I disagree with that approach I would not be in the least surprised if that is what happened here.

Still, Blizzard is trying to build a permanent set of cards for a small format this time so they have distinctly more incentive to try to make something balanced instead of just nerf cards into oblivion like they have in the past.  Hopefully they use something like my suggestion so that both Force of Nature and Savage Roar can have a place that isn't quite so frustrating for those playing against them.