The first and only non-card change is that gold acquisition through wins will be capped at 100/day. Blizzard's explanation is that it was due to certain breaches of the terms of service, and my guess is that people were using bots to concede until the matchmaker dumped them to the very bottom where ONLY bots were, and the bots would just concede to each other at random. That's a guess however, either way, it shouldn't affect most players since 100 gold/day in wins is 30 wins in a single day. Possible I suppose, but unlikely. It also has no impact on quests, arena, or achievements, so most of us won't notice a difference.
Shattered Sun Cleric
A mainstay of basically every deck ever, a 3/3 for 3 mana that gives +1/+1 to a friendly minion of your choice. Now she's just a 3/2 but is otherwise unchanged. All this really does is expose her to a lot more removal. Regardless she'll find her way into many decks, but that loss of health will make her somewhat less mandatory. Plus her main appeal was the buff she brings so I doubt anyone has seen the last of her.
Argent Bromander got hit with the nerf bat! Too bad he had Divine Shield so it didn't do anything. Like the Shattered Sun Cleric, he's lost a point of health and now sits at 2. Still, as a 4/2, Charge, Divine Shield he's in great shape and is still an assured 4 damage the turn he comes out. He might be exposed to more removal now, but I am not sure it will make the difference. Dropping him to a 3/3 might have been better, but that may also have rendered him useless. In short, I don't see the loss of health as a good reason not to put him in a deck.
I do not see this often or have it so I can't really comment; but bumping its battlecry from 2 damage to 3 might make Warlocks a tad more suicidal.
Remember when Azuriel said he'd still draft it at 10 mana? Well now we get to find out. Two more turns of safety for your big minions might sound nice but I am not sure this card is any less of a meta-changer. To be fair, some games don't get past turn 9 (though if any class is good at drawing out the game, it's Priest). I think we're still going to see it in most decks, but it means you might get some mileage out of Ragnaros and Ysera before they switch sides.
So a 2/2 is now a 2/1; Blizzard claims it was because he was too effective against Druids, Mages, and Rogues (who conveniently enough, all have AoE and hero powers that do 1 damage...) The Buzzard will still be in most decks, it just won't be a turn 2 drop or turn 1 coin. It still basically has a built in taunt, and the change to Unleash the Hounds (see below) will give it new uses (turn 6 Buzzard + Hounds for draw equal to however many minions your opponent has). Besides, my Buzzard never lives more than a turn anyways, just now Novice Engineers will be the ones killing him.
Unleash the Hounds
The most significant change; the card was once "Give your beasts +1 attack and Charge" and is now "For each enemy minion, summon a 1/1 Hound w/ Charge". Well now it fits its own title better. I like this change actually. Plenty of people are saying it makes the card worthless, but I could imagine some nice combos involving Timber Wolves, Starving Buzzards, and Unleash the Hounds. It won't have the raw power it used to, or the synergy with Snake Trap, but it also removes a mandatory Hunter card. I mean I used to feel nerfed without it.
All in all I like the changes, and I hope to see a little more variety in decks going forward.