Don't get too used to that one shot Leeroy Jenkins combo you've been nursing in Hearthstone, as Blizzard is set to nerf him along the with Hunter mainstay, Starving Buzzard, in the build up to the World Championships at Blizzcon later this year.
Leeroy will go from his current 6/2, four mana cost, to a five mana cost for the same stats. This doesn't change things up too much, but just makes him that little bit less useful and means his nastier combinations require an extra turn to take place first.
Starving Buzzard gets a much bigger change up to its mana cost, boosting it from a simple two to a much heftier five. It keeps its card drawing ability, but has its health and attack boosted along with the mana charge, making it a 3/2. This should prevent that fifth turn Starving Buzzard, Unleash the Hounds combo that Hunters rely on so much.
The nerf for these cards isn't happening immediately, so you have until the 22nd to boost your rank with them before they'll be changed forever. However, in-case you don't want them afterwards, Blizzard is also upping their disenchant value to their full cost, so you can at least trade them in for something a bit better.
Blizzard has confirmed that this will be the last balance change that takes place before the World Championships, though in the future it will continue to make tweaks and balance changes to see that a wide number of tactics are used throughout the deck building meta game.