Nerf Priests. Nerf them quickly.
After running 10 "casual" matches (a rant for another forum) and facing 5 Priests who EACH did no less than 24 damage, and 2 who actually pulled out 32 damage, IN A SINGLE ROUND I came to an unshakable truth: Priest decks are too OP. But rather than sit here and whine extensively about how decidedly unpleasant it is to watch a Priest wipe the board and then wipe me out in one round, I put my head to solving the problem of fixing them.
It's easy enough, when you get down to it. And it's so easy that I doubt anyone will want to go for it. Plus it will provide plenty of fuel to the flaming trolls.
How to fix the Priest decks:
1. Thought steal and Mind vision. The easiest fix for these cards is straightforward: The copied cards are taken from your deck count. I have seen a number of Priests who have drawn out of their decks because of a Northshire Cleric running amok. Making these two further potentially endanger your deck count will cause a lot of people to think about playing it. Yes you might draw a Heroism, but you might also pull a Murloc Raider. If a Class specific card is pulled, the mana cost for the Priest to play it is doubled.
2. Mind Control. REALLY easy fix for it, too simple to believe: Change the effect on it to read "until the end of your turn". I'm debating on the concept of leaving the creature able to active attack, IE it could attack after you MC it. Conversely, you can have the creature suffer a penalty to it's health or damage from the MC.
3. Buffs: Power Word: Shield, Divine Spirit, Inner Fire. Every Priest I have run plays this combo. Now I am not against the combo entirely, but it is insane to watch a Priest play 2 Shields, 2 Spirits and an Inner Fire to make an instant kill after they destroy your only defense creature. So how can we fix this? There's a couple options. First off, make it so that you can NOT put 2 copies of the same buff on a minion. You can even apply that to other creatures and classes as well, since there are a lot of people who want to build up an unstoppable engine of destruction. Secondly, you could also opt that IF a creature is buffed by Inner Fire, they can not attack that round. It would give players a chance to draw out some card that can help.
So there's my ideas. Feel free to rant at them, flame them and otherwise troll them to your heart's content. Since we all know Blizz doesn't read these forums, and NOTHING from them is ever implemented, I can at least fool myself into believing I tried to improve a game I enjoy.