If you've tried to play any homebrew deck in Hearthstone the past month or so, you're probably well aware of how powerful the pirate package is. Every single class that can run the strong early game pirates is running them, and everyone else is designing their decks in order to counter them. While this is usually how balance is achieved in card games, the problem with pirates is that they make each match feel incredibly similar, mostly because all three classes that run them are trying to get the same opening move.
Thankfully, during the most recent Q&A Blizzard's Designer Dean Ayala and Game Director Ben Brode have come out to say that they are keeping a close eye on the pirate package. When the Mean Streets of Gadgetzan first launched the pirate based classes represented a very high percentage of decks, but as counters got developed their popularity took a slight hit. However, they are still a bit more popular than the developers are comfortable with, and if they remain as dominant as they are currently the developers are going to step in and see how best to fix the problem.
As for what exactly the "problem" is, in their eyes its the simple fact that the pirate package is being ran in basically all decks that can use them. Furthermore, the two classes that can't use either the Reno or pirate package (Hunter and Paladin) are currently being beaten down on every turn, which is a bit of problem. According to the developers both Hunter and Paladin have a bright future in front of them, but they are currently being kept down by super efficient aggro decks, which is one of the reasons why the pirate package is currently being looked at.
That's pretty much it as far as the pirates are concerned, but if you're a fan of Hearthstone I fully recommend you check out the Q&A. Brode and Ayala have covered pretty much everything from Arena to new cards and mechanics, to the state of Wild and Standard modes, to the design goal for various classes, and so forth. There is far too much to summarize, especially since the tone is fairly conversational, so if you'd like to learn a little bit more about the future of Hearthstone you should definitely give it a look. Enjoy!