In the Hearthstone metagame there is a deck called Patron Warrior that has been a real fixture for some time now. It focuses around (surprise!) a card called Grim Patron that is a 3/3 which makes a new copy of itself if it survives damage. This effect is potentially really powerful and interacts well with all of the ways that warrior decks have to AOE the board for 1 damage or ping their own creatures. The deck can just play for value and use its synergy to try to beat the opponent down, but usually they just sit around waiting for their big combo and kill the opponent in 1 turn. (OTK)
Nobody really has a problem with the interactive Patron play that focuses on getting good value. It requires thought and strategy on both sides. However, people really don't like having full health, a few minions in play, their opponent with nothing, and then dying to a OTK combo. Players really object to having no idea what the game state is and then suddenly blowing up.
This is something that Magic dealt with back in the day when Counterspell decks, land destruction, and discard were all strong at various points. People, new players especially, absolutely hate playing against hard control where they don't get to do anything. They may not win against a superior player who just plays better creatures but at least they feel like they were playing the game.
Blizzard decided that the OTK aspect of Patron Warrior had to go and I think they were absolutely right in that regard. The trick is to figure out what part of the combo needs to die. Patron himself is iconic, has plenty of interesting tricks going on, and can be used in cool ways that aren't OTK so he isn't a good target for a nerf. What Blizzard went with instead is Warsong Commander. Right now she gives all minions that enter play with 3 or less Attack value the Charge ability so they can attack right away. This is extremely powerful when played in a combo that hopes to generate a half dozen minions in a turn, and is the engine behind the OTK. In a non combo situation like a draft she is playable, sometimes quite good, but never overpowered.
The new version of Warsong Commander loses her current ability and gains "All your Charge minions gain +1 Attack." This isn't just a complete change of her function, it also reduces her from having a good ability to having a extremely weak one. She is utterly finished in constructed play, worthless beyond belief, and in fact is so bad that she will crash to unplayable garbage status in draft too. Was this nerf on the right card, and to the right degree?
My feeling is that the answer is yes to the first question, no to the second. WC is a problem. Any new minion is going to have to be designed with the idea in mind that it may have haste from WC. If minions spawn more minions, everything has haste and keeps on beating. If anything is fragile to make up for its incredible power, it can go right away and ignore that fragility on the first turn. WC's current effect is a huge design constraint because Charge has consistently been a massive balance issue. It always will be, I suspect, and WC is a serious problem in generating OTK decks or other more general balance issues.
So what is the answer? To my mind the key thing is to make sure that WC is a powerful card in draft but not let it be a combo generator. If Blizzard wants to keep the bonus to Charge minions Attack value then WC has to have better stats - Charge isn't a common ability. If WC's cost was dropped to 2, she would be a 2/3 for 2 which is a totally reasonable pick in draft. Similarly if her stats were bumped to 3/4 and cost kept at 3, she would again be a okay draft pick even without a bonus ability. However, Warriors are absolute garbage in draft right now so I lean towards making her absolutely superb in draft to try to give them another powerful common card to use.
I would make WC a 3/4 for 3 with the ability "Your Charge minions have +2 Attack." She would be a fine body to slam down in any case, reasonably survivable, and if you have a few Charge minions she would be fantastic at making them butcher the enemy. In constructed my version of WC could end up becoming a staple in some kind of aggressive warrior deck, would be a great draft pick, and wouldn't cause any combo problems.
Blizzard is making a reasonable choice in nerfing WC to try to stop the current OTK frustration and to prevent it in future. However, when considering the rest of the game I think it is clear they should take this opportunity to change Warsong Commander into something that will shore up one of the glaring weaknesses of Hearthstone at the moment - Warrior performance in draft. Should they go forward with their stated intention WC will end up in the heap of worthless cards that nobody ever plays, and that would be a waste.