Hearthpwn

Spiked Hogrider can push for damage if you're able to remove the taunt after you play him, so he does have a strength that The Black Knight doesn't have.  Spiked Hogrider is also better and still playable when your opponent doesn't have a Taunt minion.

A 2/4 weapon is typically worth about 3 mana and summoning four 1/1 Beasts is worth 4 mana.  However, you don't get the Piranhas immediately and a 2 attack weapon can't clear much, especially on turn 5.  It does have some nice synergies by practically guaranteeing that Houndmaster, Kill command and other beast cards are always active, but overall Piranha Launcher is just too slow for Hunter, the class that wants to end games by turn 6.  It may see play in a Reno or Control Hunter list for the value it can provide, but will almost never see play in the typical Hunter decks (Face, Secret, or Midrange).

Scientist is worth about 5 mana in value.  Minibot is worth 2.5.  The two aren't remotely comparable.  One is slightly OP (Minibot) while the other is insanely broken (Scientist).

Seal of Champions is probably the best buff spell paladin has access to in arena, yet in constructed it's actually quite a bit worse than Blessing of Kings and Blessing of Might.  This is because you trade into bigger minions so much more often in arena.  You get to actually use the divine shield to clear a high attack minion while keeping your minion at full health.  This almost never happens in constructed due to much fewer bigger minions seeing play.  Bog Creepers, Krakens, Ogres, Yetis, and all those big healthy minions are quite common in arena, but in constructed they're replaced with removal spells, AoEs, weaker minions with battlecries or deathrattles, and a lot of tokens.  This means that making a big trade in constructed is almost never going to happen like it does in arena, so Seal of Champions becomes much weaker, especially with all the light damage effects such as Maelstrom Portal, Blood to Ichor, and more.  In short, Seal of Champions in a great arena card but a mediocre constructed card by the circumstances of both formats.

This card has been everywhere in the past few weeks.  I understand why (Midrange Shaman and Spirit Claws), but man does he get annoying to play against after the tenth time he puts your Gorehowl or Atiesh or Ashbringer in a museum.  Regardless, very solid card.

Still incredibly powerful and an auto-include in all Hunter decks even at 9 mana.  Probably will need to be nerfed to 10 mana at some point.

Rockbiter Weapon is now on par with Heroic Strike, which isn't a bad card by any means.  You get 1 less damage from Rockbiter compared to Heroic, but in return you receive the flexibility of putting Rockbiter on a minion.  Shaman also has a wide selection of good windfury cards, which are still great with Rockbiter.  It's definitely weaker than before, but could still see some play when used with Doomhammer or Al'Akir.

Such a crutch for bad players, can't wait for it to be gone in 3 days.

the devs were thinking about nerfing this card but at the last moment they changed their minds.

...sorry

Whenever I see dev comments on balance (like Kidnapper being "hyper frustrating"), I think of cards like this and wonder if they are even playing the same game as we are.

The meta will be a lot more interesting with this shit gone.