Jahn and I built this sick-ass Zul'Jin beast hunter deck and climbed from rank 17 to rank 4 in an evening. Basically, you run master's call, unleash the hounds, animal companion, dire frenzy, and unleash the beast with Zul'Jin. When you Zul, you fill your board with animal companions, hounds, and 5/5 rushers, and completely fill up your hand with beasts from your deck and twinspelled copies of unleash the beast. Meanwhile, you keep your deck full of buffed beasts with dire frenzy. The tempo and card advantage you get is hard for most decks to beat. Meanwhile, in the early game, you have a bunch of cheap beasts (hyena, hog knight, springpaw, shimmerfly, dire wolf alpha, hungry crab) to pressure their life total hard, headhunter's hatchet to dominate the early board, and dire frenzy/master's call to reload midgame. You can be a hunter deck and just kill them, and you can also outvalue them with Zul. Even if you can't outvalue them, the tempo you get from Zul can easily be lethal to them if they're already low from your early game.

So what are the deck's weaknesses? Well, hunter's usual weakness is losing board early, because they struggle to come back, and so much of your game plan depends on being able to get early damage in and make their life total matter, which you can't do if you're behind on board instead of ahead. However, you have hatchet, which is an insane tempo tool, plenty of early drops, and you just randomly destroy murloc shaman by running 2 crab. The two decks that stand a good chance of kicking you off the board are secret paladin, and zoo warlock, and these are where you can struggle. The other weakness of aggressive hunter decks is that they can easily run out of gas, but you have enough value between shimmerfly, master's call, unleash the beast, and Zul'Jin ensure that you rarely do.

Anyways, my final thought about the new format is that we ran into a bunch of bomb warrior on ladder and I have no idea why people play it. Control warrior is probably the deck in which random face burn is the most useless, since you don't pressure their life total naturally, so the only way they die to it is if you've already attritioned them out and are ahead on board, and at that point you've already won anyways and don't need the bombs. I think you're better off playing cards that help you reach that state of attrition than cards that only matter once you're already there.

So far, I've had the most success with a straightforward tempo pirate Rogue deck:



The game plan is simple: grab the board with swingy tempo plays in turns 3-4 (Blink Fox into 0-cost Vendettas, Wagglepick into 0-cost Corsairs, Prep-Evis-Edwin, etc.), hold it for a turn or two while beating on their face, then finish them off just as they're about to take full control and/or overrun you.

I started with a Deathrattle Hunter with Zul'jin, which has gone 2-1 so far.

Personally, I've just been jamming arena runs until the meta shakes out, and I know what I need to craft.