It took Magic The Gathering a long time to figure out what sort of deck is fun to play against and force the competitive scene to look like that deck. Having seen the first reveals of the new Hearthstone set I think Hearthstone is being deliberately pushed that same way.
People like games that are over in a predictable time span. They like decks that try to do exciting things. They want to see big swings.
What they don't like is games where a control deck just kills everything the opponent puts out and then sits there waiting for them to die.
In Magic the control deck that was most hated was the permission deck, where the permission player constantly counters anything the opponent tries to do. It just sucks to sit there watching all of your schemes fall apart while your opponent prepares to bore you to death.
Don't get me wrong, I loved playing those decks, but my opponents generally did not, and that was the problem. It isn't that nobody loves permission decks, just that most people don't, and the fact that their games take forever to finish is frustrating for casual players and a problem for tournaments.
Hearthstone has a similar sort of thing with Control Warrior. CW sits there gaining health and killing your stuff and waiting for you to die. It isn't fun.
In the last expansion Blizzard put out a new archetype called Jade. Jade cards make Jade Golems, which start out at 1/1 and grow by +1/+1 each time. Those cards start out weak but eventually the Jade Golems become 10/10 or more, and the opposing player just folds under the pressure. A lot of people talked about how as long as Jades are in the game no other control deck can succeed because eventually Jade Golems overwhelm any other deck. Many people posited this as a problem. I think it is the solution, and is quite deliberate on Blizzard's part. We just need more things like it.
The reason I think it is deliberate is the selection of new cards coming out in the next expansion. The most obvious example is this Lakkari Sacrifice, which gives you the following card:
Nether Portal is a new type of card that sits on the battlefield like a minion, but cannot be removed. Each turn it makes a pair of 3/2 Imps, one on each side of it. Actually getting the Nether Portal card requires a lot of investment but once you get it you reap the value every turn thereafter. Unless your opponent has some source of extreme value themselves you will absolutely crush them in the late game, no question.
This card *crushes* CW. If your opponent plays this you can't just sit there trying to gain health and clear their board because they will have far more than you can handle. Just like Jade decks this card is designed to flat out beat any deck that isn't able to proactively attack them.
What this means for the metagame is that people will be playing control decks that quickly get to a powerful win condition that cannot be stopped. The only solution is to either crush them quickly with an aggro deck, or to set up your own amazing win condition faster or better than they do. I think this second option is what Blizzard is aiming for. They think, and I agree, that the game is most fun when people are battling for board control and life totals and ratcheting up the stakes each turn. When both players have totally nutty things they can do that will end the game one way or the other the game is never going to coast or get boring. Each turn is going to contain steps towards something game changing happening.
CW is going to *suck* in that metagame. This is a good thing for Hearthstone, just as permission decks sucking was a good thing for Magic. That doesn't mean that all decks should be control decks, and it certainly doesn't mean that everyone is going to include these win conditions, but if the design team does their work at all well, a lot of people will. That struggle towards victory with people threatening their gigantic bomb cards is a lot more fun than a long attrition match.
This style of game will mean that control vs. control matchups will be exciting, much quicker than before, and involve a lot of early game action. People will be pushing to get their engine going rather than just sitting there staring at one another.
Whether or not they get the numbers right is a real question. I can't answer that yet, both because I haven't seen all the cards, and because predicting that sort of thing is extremely difficult. However, I can say that I love the concept of control decks with powerful win conditions and I think the games that come out of that will be more exciting to play and to watch. I am really looking forward to seeing what else is in the next expansion and watching the metagame that comes out of it.